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The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION

Dated May 8, 2006

Filed Pursuant to Rule 424(b)(3)
Registration No. 333-132104

Preliminary Prospectus Supplement
May 8, 2006
(To Prospectus dated February 28, 2006)

$                  


LOGO
 
Abbott

Abbott Laboratories

$                      % Notes due 20    

$                      % Notes due 20    

$                      % Notes due 20    

        We are offering $                  aggregate principal amount of    % Notes due 20    (the "20 Notes"), $                  aggregate principal amount of    % Notes due 20    (the "20 Notes") and $                  aggregate principal amount of    % Notes due 20    (the "20 Notes" and, together with the 20    Notes and the 20    Notes, the "notes"). Interest on the notes will be paid semi-annually in arrears on            and            of each year, beginning on            , 2006. The 20    Notes will mature on                        , 20    , the 20    Notes will mature on                        , 20    , and the 20    Notes will mature on                        , 20    . We may redeem some or all of the notes at any time and from time to time at our option. The redemption prices are discussed under the heading "Description of Notes—Redemption of the Notes."

        The notes will be our general unsecured senior obligations and will rank equally with all of our other unsecured senior indebtedness from time to time outstanding.

        Investing in the notes involves risks. See "Risk Factors" beginning on page S-3 of this prospectus supplement.
 
   Price to
Public(1)
   Underwriting
Discounts
   Proceeds, before
expenses, to Us
Per 20    Note   %   %   %
Total   $   $   $
Per 20    Note   %   %   %
Total   $   $   $
Per 20    Note   %   %   %
Total   $   $   $
(1)
Plus accrued interest from May     , 2006, if settlement occurs after that date.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

        The notes will not be listed on any national securities exchange. Currently, there is no public market for the notes.

        The underwriters expect to deliver the notes in book-entry form only through the facilities of The Depository Trust Company for the accounts of its participants, including Clearstream Banking, societe anonyme, and Euroclear Bank S.A./N.V., as operator of the Euroclear System, against payment in New York, New York on May     , 2006.

Joint Book-Running Managers

ABN AMRO Incorporated Banc of America Securities LLC JPMorgan   Morgan Stanley

Senior Co-Managers

Co-Managers


TABLE OF CONTENTS

Prospectus Supplement

 
   Page
About this Prospectus Supplement   S-ii
Abbott Laboratories   S-1
Recent Developments   S-1
Risk Factors   S-3
Cautionary Statement Regarding Forward-Looking Statements   S-5
Use of Proceeds   S-6
Ratio of Earnings to Fixed Charges   S-6
Capitalization   S-7
Description of Notes   S-8
Material U.S. Federal Income Tax Considerations   S-13
Underwriting   S-17
Legal Opinions   S-19

Prospectus

 
   Page
About this Prospectus   2
Abbott Laboratories   2
Use of Proceeds   2
Description of Debt Securities   3
Legal Opinions   11
Experts   12
Where You Can Find More Information   12

S-i


ABOUT THIS PROSPECTUS SUPPLEMENT

        This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part, the accompanying prospectus, gives more general information, some of which may not apply to this offering. You should read the entire prospectus supplement, as well as the accompanying prospectus and the documents incorporated by reference that are described under "Where You Can Find More Information" in the accompanying prospectus.

        You should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus, and the documents incorporated by reference is accurate only as of respective dates of those documents in which the information is contained. Our business, financial condition, results of operations, and prospects may have changed since those dates.

        References to "Abbott," "we," "us," and "our" in this prospectus supplement and the accompanying prospectus are to Abbott Laboratories, or Abbott Laboratories and its consolidated subsidiaries, as the context requires.

S-ii


ABBOTT LABORATORIES

        Abbott Laboratories is an Illinois corporation, incorporated in 1900. Abbott's principal business is the discovery, development, manufacture, and sale of a broad and diversified line of health care products. Abbott's products are generally sold directly to retailers, wholesalers, hospitals, health care facilities, laboratories, physicians' offices and government agencies throughout the world.

        Effective January 1, 2006, Abbott's segments were reorganized to reflect the shift of nutritional products from Abbott's International division to a newly formed division, Abbott Nutrition International. As a result of this reorganization, total assets of approximately $850 million have been transferred from the International division to the Abbott Nutrition International Products division. For segment reporting purposes, Abbott's Ross Products division and the Abbott Nutrition International division are aggregated and reported as the Nutritional Products segment and the U.S. and international pharmaceutical products divisions are aggregated and reported as the Pharmaceutical Products segment. Abbott also has a 50 percent owned joint venture, TAP Pharmaceutical Products Inc. In connection with Boston Scientific Corporation's ("Boston Scientific") acquisition of Guidant Corporation ("Guidant") consummated on April 21, 2006, Abbott purchased Guidant's vascular intervention and endovascular solutions businesses.

        Abbott's reportable segments are as follows:

        Pharmaceutical Products—Worldwide sales of a broad line of pharmaceuticals. For segment reporting purposes, two pharmaceutical divisions are aggregated and reported as the Pharmaceutical Products segment.

        Diagnostic Products—Worldwide sales of diagnostic systems and tests for blood banks, hospitals, consumers, commercial laboratories and alternate-care testing sites. Since January 1, 2004, for segment reporting purposes, four diagnostic divisions have been aggregated and reported as the Diagnostic Products segment.

        Nutritional Products—Worldwide sales of a broad line of adult and pediatric nutritional products. For segment reporting purposes, two nutrition divisions are aggregated and reported as the Nutritional Products segment.

        Under an agreement between Abbott and Takeda Pharmaceutical Company, Limited of Japan ("Takeda"), TAP Pharmaceutical Products Inc. (owned 50 percent by Abbott and 50 percent by an affiliate of Takeda), together with its subsidiary, TAP Pharmaceuticals Inc. ("TAP"), develops and markets pharmaceutical products primarily for the United States and Canada. TAP's products are generally sold directly to physicians, retailers, wholesalers, health care facilities, and government agencies.


RECENT DEVELOPMENTS

        On April 21, 2006, Abbott announced the completion of its acquisition of substantially all of the vascular intervention and endovascular solutions businesses of Guidant (the "Business") for $4.1 billion in cash. As part of this acquisition, Abbott has also agreed to make two milestone payments, each in the amount of $250 million. One milestone payment will be made after the receipt by Abbott of approval from the U.S. Food and Drug Administration to market an everolimus eluting stent in the United States. The other milestone payment will be made after the receipt by Abbott of a similar approval in Japan, provided, in each case, that the regulatory approval is on or before April 21, 2016. Abbott has also assumed certain liabilities relating to the Business.

        Additionally, Abbott loaned BSC International Holding Limited, (a wholly-owned subsidiary of Boston Scientific) $900 million on a subordinated basis. This loan is payable on April 21, 2011, accrues

S-1


interest on its outstanding principal amount at a rate of 4.00% per annum, and is unconditionally guaranteed by Boston Scientific.

        Abbott also purchased 64,635,272 shares of Boston Scientific stock for $1.4 billion. Within 18 months after the acquisition of the Business, Boston Scientific will issue additional shares of Boston Scientific stock to Abbott having an aggregate value of up to $60 million (based on the average closing price of Boston Scientific common stock during the 20 consecutive trading day period ending five trading days prior to the date of issuance of those shares) to reimburse Abbott for the cost of borrowing associated with Abbott's purchase of the 64,635,272 shares of Boston Scientific stock. Abbott must vote the Boston Scientific shares it acquired in the transaction proportionally with the vote cast by all other Boston Scientific stockholders. Abbott has agreed to limit the number of shares of Boston Scientific stock that it sells in any month. Abbott will apply a portion of net proceeds from any sale of these shares of Boston Scientific stock in excess of specified amounts to reduce the principal amount of the loan from Abbott to BSC International Holding Limited. Abbott is required to dispose of all of these shares within 30 months following the acquisition of the Business.

        Abbott funded the acquisition of the Business, the loan and the purchase of Boston Scientific stock by using approximately $2.3 billion in existing cash and $4.1 billion from the issuance of short term debt.

S-2

RISK FACTORS

        Before you decide to invest in the notes, you should consider the factors set forth below as well as the risk factors discussed in our Annual Report on Form 10-K for the year ended December 31, 2005 and our Quarterly Report on Form 10-Q for the period ended March 31, 2006, which are incorporated by reference into this prospectus supplement and the accompanying prospectus. See "Where You Can Find More Information" in the accompanying prospectus.

A public trading market for the notes may not develop.

        We have not applied and do not intend to apply for listing of the notes on any securities exchange or any automated quotation system. As a result, a market for the notes may not develop or, if one does develop, it may not be sustained. If an active market for the notes fails to develop or cannot be sustained, the trading price and liquidity of the notes could be adversely affected.

The market price of the notes may be volatile.

        The market price of the notes will depend on many factors that may vary over time and some of which are beyond our control, including:

        As a result of these factors, you may only be able to sell your notes at prices below those you believe to be appropriate, including prices below the price you paid for them.

An increase in interest rates could result in a decrease in the relative value of the notes.

        In general, as market interest rates rise, notes bearing interest at a fixed rate generally decline in value because the premium, if any, over market interest rates will decline. Consequently, if you purchase these notes and market interest rates increase, the market value of your notes may decline. We cannot predict the future level of market interest rates.

Ratings of each series of notes may not reflect all risks of an investment in the notes.

        We expect that the notes will be rated by at least one nationally recognized statistical rating organization. The ratings of the notes will primarily reflect our financial strength and will change in accordance with the rating of our financial strength. Any rating is not a recommendation to purchase, sell, or hold the notes. These ratings do not correspond to market price or suitability for a particular investor. In addition, ratings at any time may be lowered or withdrawn in their entirety.

The notes do not restrict our ability to incur additional debt or prohibit us from taking other action that could negatively impact holders of the notes.

        We are not restricted under the terms of the indenture governing the notes or the notes from incurring additional indebtedness. The terms of the indenture limit our ability to secure additional debt without also securing the notes and to enter into sale and leaseback transactions. However, these limitations are subject to numerous exceptions. See "Description of Debt Securities—Certain Covenants

S-3


of the Company" in the accompanying prospectus. In addition, the notes do not require us to achieve or maintain any minimum financial results relating to our financial position or results of operations. Our ability to recapitalize, incur additional debt, secure existing or future debt, or take a number of other actions that are not limited by the terms of the indenture and the notes, including repurchasing indebtedness or common or preferred stock or paying dividends, could have the effect of diminishing our ability to make payments on the notes when due.

Our financial performance and other factors could adversely impact our ability to make payments on the notes.

        Our ability to make scheduled payments with respect to our indebtedness, including the notes, will depend on our financial and operating performance, which, in turn, are subject to prevailing economic conditions and to financial, business, and other factors beyond our control.

The notes will be unsecured and subordinated to our secured debt, which makes the claims of holders of secured debt senior to the claims of holders of the notes.

        The notes will be unsecured. As of March 31, 2006, we did not have any significant secured debt outstanding. The holders of any secured debt that we may have may foreclose on our assets securing our debt, reducing the cash flow from the foreclosed property available for payment of unsecured debt. The holders of any secured debt that we may have also would have priority over unsecured creditors in the event of our liquidation. In the event of our bankruptcy, liquidation, or similar proceeding, the holders of secured debt that we may have would be entitled to proceed against their collateral, and that collateral will not be available for payment of unsecured debt, including the notes. As a result, the notes will be effectively subordinated to any secured debt that we may have.

The notes are effectively subordinated to the liabilities of our subsidiaries, which may reduce our ability to use the assets of our subsidiaries to make payments on the notes.

        The notes are not guaranteed by our subsidiaries and therefore the notes will be effectively subordinated to all existing and future indebtedness and other liabilities of our subsidiaries. In the event of a bankruptcy, liquidation, or similar proceeding of a subsidiary, following payment by the subsidiary of its liabilities, the subsidiary may not have sufficient assets to make payments to us. As of March 31, 2006, our subsidiaries had approximately $2.6 billion of outstanding indebtedness (excluding intercompany debt and liabilities and accounts payable incurred in the ordinary course of business).

S-4


CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

        This prospectus supplement and the accompanying prospectus and the documents incorporated by reference include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements are based on management's current expectations, estimates, and projections. Words such as "expects," "anticipates," "intends," "plans," "believes," "seeks," "estimates," "forecasts," variations of these words, and similar expressions are intended to identify these forward-looking statements. Certain factors, including but not limited to those identified under the heading "Risk Factors" in this prospectus supplement, as well as in Item 1A, "Risk Factors," and Exhibit 99.1 to our Annual Report on Form 10-K for the year ended December 31, 2005 and in Item 1A, "Risk Factors," to our Quarterly Report on Form 10-Q for the period ended March 31, 2006, which are incorporated by reference into this prospectus supplement and the accompanying prospectus, may cause actual results to differ materially from current expectations, estimates, projections, and forecasts and from past results. You are cautioned not to place undue reliance on such statements, which speak only as of the date made. Abbott undertakes no obligation to release publicly any revisions to forward-looking statements as the result of subsequent events or developments.

S-5


USE OF PROCEEDS

        We estimate the net proceeds to us from the sale of the notes will be approximately $                  , after deducting underwriting discounts and estimated offering expenses payable by us. We intend to use the net proceeds from the sale of the notes to repay commercial paper indebtedness incurred to make a loan in the original principal amount of $900 million to Boston Scientific, to make an equity investment of $1.4 billion in Boston Scientific and to fund the $4.1 billion acquisition of Guidant's vascular intervention and endovascular solutions businesses. See "Recent Developments." The indebtedness to be repaid is of varying maturities of less than one year. As of April 21, 2006, Abbott's outstanding principal balance of commercial paper was approximately $4.1 billion, at a weighted average interest rate of 4.77%. Pending any specific application, the net proceeds from the offering may be invested in short-term marketable securities.


RATIO OF EARNINGS TO FIXED CHARGES

        The following table sets forth our ratio of earnings to fixed charges for the periods indicated.

 
    
    
    
    
    
    
   Three Months
Ended
March 31
   Pro Forma
Three Months
Ended
March 31,
2006
 
   Fiscal Year Ended December 31
    
 
   Pro Forma Year Ended
December 31,
2005
 
   2001
   2002
   2003
   2004
   2005
   2005
   2006
Ratio of earnings to fixed charges   5.0   12.0   14.5   16.5   14.8       15.9   12.9    

        For purposes of calculating the ratio of earnings to fixed charges, earnings have been calculated by adjusting earnings from continuing operations for taxes on earnings from continuing operations, interest expense, amortization of capitalized interest, net of capitalized interest, minority interest, and the portion of rentals representative of the interest factor. Abbott considers one-third of rental expense to be the amount representing return on capital. Fixed charges comprise total interest expense, including capitalized interest and such portion of rentals. The unaudited pro forma ratio of earnings to fixed charges gives effect to increased interest expense from the issuance of the notes and the reduction of interest expense resulting from any outstanding commercial paper during the pro forma periods noted above. For the year ended December 31, 2005, the pro forma computation reflects the repayment of a monthly average of approximately $1.3 billion of commercial paper. There were no commercial paper borrowings during the three months ended March 31, 2006.

S-6


CAPITALIZATION

        The following table sets forth, as of March 31, 2006, Abbott's consolidated capitalization (i) on a historical basis and (ii) on a pro forma basis to give effect to the issuance of the notes. See "Use of Proceeds" and "Recent Developments." You should read the table together with our consolidated financial statements and the notes thereto incorporated by reference into this prospectus supplement and the accompanying prospectus.

 
   Actual
   Pro Forma
 
   (In Thousands)
Long Term Debt:            
5.625% Notes due 2006   $ 1,600,000   $ 1,600,000
6.4% Notes due 2006     250,000     250,000
0.77% Yen Notes due 2007     86,081     86,081
Notes, variable interest above LIBOR, due 2008     345,000     345,000
Euro notes, variable interest above LIBOR, due 2008     639,522     639,522
British Pound notes, variable interest above LIBOR, due 2008     348,000     348,000
6.0% Notes due 2008     200,000     200,000
5.4% Notes due 2008     200,000     200,000
1.05% Yen Notes due 2008     430,404     430,404
3.5% Notes due 2009     500,000     500,000
1.51% Yen Notes due 2010     129,121     129,121
3.75% Notes due 2011     500,000     500,000
1.95% Yen Notes due 2013     215,202     215,202
4.35% Notes due 2014     500,000     500,000
Other, including fair market value adjustments relating to interest rate hedge contracts designated as fair value hedges     56,925     56,925
% Notes due        offered hereby     —      
% Notes due        offered hereby     —      
% Notes due        offered hereby     —      
   
 
  Total long term debt   $ 6,000,255   $  
  Total shareholders' investment     14,442,145     14,442,145
   
 
    Total capitalization   $ 20,442,400   $  
   
 

S-7


DESCRIPTION OF NOTES

        The following summary of the particular terms of the notes offered by this prospectus supplement supplements and, to the extent inconsistent with the accompanying prospectus, replaces the description of the general terms and provisions of the securities contained in the accompanying prospectus, to which description reference is made by this prospectus supplement. The statements in this prospectus supplement concerning the notes and the indenture (as defined below) do not purport to be complete. All such statements are qualified in their entirety by reference to the accompanying prospectus and the provisions of the indenture, the form of which has been filed with the Securities and Exchange Commission.

        Abbott will issue the notes under an indenture, dated as of February 9, 2001, as supplemented by a supplemental indenture, dated as of February 27, 2006 (as so supplemented, the "indenture"), between Abbott and J.P. Morgan Trust Company, N.A. (as successor to Bank One Trust Company, N.A.), as trustee (the "trustee"). For a description of the rights attaching to different series of debt securities under the indenture, see "Description of Debt Securities" in the accompanying prospectus.

Title

        % Notes due                        , 20    .

        % Notes due                        , 20    .

        % Notes due                        , 20    .

Total Initial Principal Amount of Notes

        The 20 Notes: $                  .

        The 20 Notes: $                  .

        The 20 Notes: $                  .

        Abbott may from time to time, without notice to or the consent of the holders of the notes, issue additional series of securities under the indenture or additional notes of a series of notes. These additional notes may be consolidated and form a single series with an existing series of the notes and have the same terms as to status, redemption or otherwise as such series of notes (except for the issue date and the public offering price). For purposes of this description, any reference to notes of a series shall include any notes of the same series issued after the closing of this offering.

Maturity of Notes

        The 20 Notes will mature on                        , 20    .

        The 20 Notes will mature on                        , 20    .

        The 20 Notes will mature on                        , 20    .

Interest Rate on Notes

        The interest rate on the 20 Notes is    % per year, computed on the basis of a 360-day year of twelve 30-day months.

        The interest rate on the 20 Notes is    % per year, computed on the basis of a 360-day year of twelve 30-day months.

        The interest rate on the 20 Notes is    % per year, computed on the basis of a 360-day year of twelve 30-day months.

S-8


Date Interest Begins to Accrue on Notes

        Interest will begin to accrue on the 20 Notes on May     , 2006.

        Interest will begin to accrue on the 20 Notes on May     , 2006.

        Interest will begin to accrue on the 20 Notes on May     , 2006.

Interest Payment Dates

        Abbott will pay interest on the notes semi-annually on each            and            (each, an "interest payment date"). Interest payable on each interest payment date will include interest accrued from May     , 2006 or from the most recent interest payment date to which interest has been paid or duly provided for.

First Interest Payment Date

                                , 2006.

Regular Record Dates for Interest

        Abbott will pay interest payable on any interest payment date to the person in whose name a note (or any predecessor note) is registered at the close of business on                        or                         , as the case may be, next preceding such interest payment date.

Paying Agent

        The trustee will initially be the securities registrar and paying agent and will act as such only at its offices in New York, New York. Abbott may at any time designate additional paying agents or rescind the designations or approve a change in the offices where they act.

Global Securities

        The notes will be represented by one or more global securities registered in the name of the nominee of The Depository Trust Company ("DTC"). Abbott will only issue the notes in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof. Abbott will deposit the global securities with DTC or its custodian and will register the global securities in the name of DTC's nominee. See "Description of Debt Securities—Book-Entry Securities" in the accompanying prospectus. Indirect access to DTC's system is also available to other entities such as Clearstream Luxembourg, Euroclear, banks, brokers, dealers and trust companies (collectively, the "indirect participants") that clear through or maintain a custodial relationship with a participant, either directly or indirectly. Investors who are not participants may beneficially own securities held by or on behalf of DTC only through participants or indirect participants.

        Clearstream Luxembourg.    Clearstream Banking, societe anonyme ("Clearstream Luxembourg"), is incorporated under the laws of Luxembourg as a professional depositary. Clearstream Luxembourg holds securities for its participating organizations ("Clearstream Luxembourg Participants") and facilitates the clearance and settlement of securities transactions between Clearstream Luxembourg Participants through electronic book-entry changes in accounts of Clearstream Luxembourg Participants, thereby eliminating the need for physical movement of certificates. Clearstream Luxembourg provides Clearstream Luxembourg Participants with, among other things, services for safekeeping, administration, clearance and establishment of internationally traded securities and securities lending and borrowing. Clearstream Luxembourg interfaces with domestic markets in several countries. As a professional depositary, Clearstream Luxembourg is subject to regulation by the Luxembourg Monetary Institute. Clearstream Luxembourg Participants are recognized financial

S-9


institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations, and may include the underwriters. Indirect access to Clearstream Luxembourg is also available to others, such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Clearstream Luxembourg Participant either directly or indirectly.

        Distributions with respect to notes held beneficially through Clearstream Luxembourg will be credited to cash accounts of Clearstream Luxembourg Participants in accordance with its rules and procedures to the extent received by the U.S. Depositary for Clearstream Luxembourg.

        Euroclear.    Euroclear was created in 1968 to hold securities for participants of Euroclear ("Euroclear Participants") and to clear and settle transactions between Euroclear Participants through simultaneous electronic book-entry delivery against payment, thereby eliminating the need for physical movement of certificates and any risk from lack of simultaneous transfers of securities and cash. Euroclear includes various other services, including securities lending and borrowing and interfaces with domestic markets in several markets in several countries. Euroclear is operated by Euroclear Bank S.A./N.V. (the "Euroclear Operator"), under contract with Euro-clear Clearance Systems S.C., a Belgian cooperative corporation (the "Cooperative"). All operations are conducted by the Euroclear Operator, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator, not the Cooperative. The Cooperative establishes policy for Euroclear on behalf of Euroclear Participants. Euroclear Participants include banks (including central banks), securities brokers and dealers and other professional financial intermediaries and may include the underwriters. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear Participant, either directly or indirectly.

        The Euroclear Operator is regulated and examined by the Belgian Banking Commission. Distributions of principal and interest with respect to notes held through Euroclear or Clearstream Luxembourg will be credited to the cash accounts of Euroclear or Clearstream Luxembourg participants in accordance with the relevant system's rules and procedures, to the extent received by such system's depositary.

        Links have been established among DTC, Clearstream Luxembourg and Euroclear to facilitate the initial issuance of the notes and cross-market transfers of the notes associated with secondary market trading. DTC will be linked indirectly to Clearstream Luxembourg and Euroclear through the DTC accounts of their respective U.S. depositaries.

Redemption of the Notes

        Abbott may redeem each series of the notes, at any time in whole or from time to time in part, at a redemption price equal to:


        "Treasury Yield" means, with respect to any notes being redeemed, the yield to maturity implied by (i) the yields reported as of the third business day prior to the redemption date, on (a) the

S-10

Bloomberg Financial Markets News screen PX1 or the equivalent screen provided by Bloomberg Financial Markets News, or (b) if such on-line market data is not at that time provided by Bloomberg Financial Markets News, on the display designated as "Page 500" on the Moneyline Telerate service (or such other display as may replace Page 500 on the Moneyline Telerate service), in any case for actively traded U.S. Treasury securities having a maturity equal to the remaining term of those notes as of the redemption date, or (ii) if such yields are not reported at that time or the yields reported as of that time are not ascertainable (including by way of interpolation), the Treasury constant maturities yields reported, for the latest day for which such yields have been so reported at that time, in Federal Reserve Statistical Release H.15 (519) (or any comparable successor publication) for actively traded U.S. Treasury securities having a constant maturity equal to the remaining term of those notes as of such redemption date. Such implied yield will be determined, if necessary, by (x) converting U.S. Treasury bill quotations to bond-equivalent yields in accordance with accepted financial practice and (y) interpolating linearly between (1) the actively traded U.S. Treasury security with a maturity closest to and greater than the remaining term of those notes and (2) the actively traded U.S. Treasury security with a maturity closest to and less than the remaining term of those notes.

        If we exercise our right to redeem all or fewer than all of the notes, we will publish a notice in the manner described under the heading "Description of Debt Securities—Book-Entry Securities" in the accompanying prospectus. Each notice of redemption will specify the provisions of the notes under which the redemption is made, the date the notes will be redeemed, the place of payment and the estimated redemption price. If any note is to be redeemed in part only, the notice of redemption will state the portion of the principal amount of the note to be redeemed and will state that upon surrender of the note, a note or notes of the same series will be issued in principal amount equal to the unredeemed portion. If less than all of the notes are to be redeemed, the trustee will select the numbers of notes to be redeemed in part in any manner the trustee deems fair and appropriate. If we redeem only some of the notes, DTC's practice is to choose by lot the amount to be redeemed from the notes held by each of its participating institutions. DTC will give notice to these participants, and these participants will give notice to any "street name" holders of any beneficial interests in the notes according to arrangements among them. These notices may be subject to statutory or regulatory requirements.

        We will not be responsible for giving notice of redemption of the notes to anyone other than DTC. Owners of beneficial interests in a global note will receive notice as described under the heading "Description of Debt Securities—Book-Entry Securities" in the accompanying prospectus. If we deliver a notice of redemption in accordance with the indenture, the notes or portions of notes with respect to the notice will become due and payable on the date and at the place of payment stated in the notice at the applicable redemption price, together with interest, if any, accrued to the date fixed for redemption, and on and after such date (unless we are in default in the payment of the notes at the redemption price, together with interest, if any, accrued to such date) interest on the notes or portions of notes called for redemption will cease to accrue. Each series of the notes, if not the subject of any early optional redemption, will be redeemed at their maturity at their principal amount plus any accrued and unpaid interest.

Trading in DTC

        Indirect holders trading their beneficial interests in the global securities through DTC must trade in DTC's same-day funds settlement system and pay in immediately available funds.

Sinking Fund

        There is no sinking fund.

S-11


Defeasance

        The notes are subject to Abbott's ability to choose "legal defeasance" and "covenant defeasance" as described under the caption "Description of Debt Securities—Defeasance and Covenant Defeasance" in the accompanying prospectus.

Definitive Securities

        A permanent global security is exchangeable for definitive notes registered in the name of any person other than DTC or its nominee, only if:

        (a)   DTC notifies Abbott that it is unwilling or unable to continue as depositary for the global securities or if at any time DTC ceases to be a clearing agency registered under the Securities Exchange Act of 1934, as amended, and Abbott does not appoint a successor within 90 days;

        (b)   in Abbott's discretion at any time, Abbott determines not to have all of the notes represented by the global securities and notifies the trustee; or

        (c)   an event of default, as described under the caption "Description of Debt Securities—Events of Default" in the accompanying prospectus, has occurred and is continuing with respect to the notes.

Same-Day Settlement and Payment

        The underwriters will make settlement for the notes in immediately available or same-day funds. So long as the notes are represented by the global securities, Abbott will make all payments of principal and interest in immediately available funds.

        Secondary trading in notes and debentures of corporate issuers is generally settled in clearing-house or next-day funds. In contrast, so long as the notes issued in this offering are represented by the global securities registered in the name of DTC or its nominee, the notes will trade in DTC's Same-Day Funds Settlement System. DTC will require secondary market trading activity in the notes represented by the global securities to settle in immediately available or same-day funds. Abbott cannot give any assurances as to the effect, if any, of settlement in same-day funds on trading activity in the notes.

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MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS

        This discussion is of a general nature and is included herein solely for information purposes. This summary is not intended to be, and should not be, construed to be legal or tax advice. No representation with respect to the consequences to any particular purchaser of the notes is made. Prospective purchasers should consult their own advisors with respect to their particular circumstances.

        The following is a summary of the material U.S. federal income tax consequences to U.S. holders and non-U.S. holders (each as defined below) relating to the purchase, ownership, and disposition of the notes. This discussion is based upon current provisions of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"), existing and proposed Treasury regulations promulgated thereunder, rulings, pronouncements, judicial decisions, and administrative interpretations of the Internal Revenue Service, all of which are subject to change, possibly on a retroactive basis, at any time by legislative, judicial, or administrative action. We cannot assure you that the Internal Revenue Service will not challenge the conclusions stated below, and no ruling from the Internal Revenue Service has been (or will be) sought on any of the matters discussed below.

        The following discussion does not purport to be a complete analysis of all the potential U.S. federal income tax effects relating to the purchase, ownership, and disposition of the notes. Without limiting the generality of the foregoing, the discussion does not address the effect of any special rules applicable to certain types of holders, including, without limitation, dealers in securities or currencies, insurance companies, financial institutions, thrifts, regulated investment companies, tax-exempt entities, U.S. persons whose functional currency is not the U.S. dollar, U.S. expatriates, persons who hold notes as part of a straddle, hedge, conversion transaction, or other risk reduction or integrated investment transaction, investors in securities that elect to use a mark-to-market method of accounting for their securities holdings, individual retirement accounts or qualified pension plans, or investors in pass through entities, including partnerships and Subchapter S corporations. In addition, this discussion is limited to holders who are the initial purchasers of the notes at their original issue price and hold the notes as capital assets within the meaning of Section 1221 of the Internal Revenue Code. This discussion does not address the effect of any U.S. state or local income or other tax laws, any U.S. federal estate and gift tax laws, any foreign tax laws, or any tax treaties.

U.S. Holders

        The term "U.S. holder" means a beneficial owner of a note that is:


        All of the notes bear interest at a fixed-rate or will bear interest at a floating rate that is either a qualified floating rate or an objective rate under the rules regarding original issue discount. Moreover,

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we do not intend to issue the notes at a discount that will exceed a de minimis amount of original issue discount. Accordingly, interest on a note will generally be includable in income of a U.S. holder as ordinary income at the time the interest is received or accrued, in accordance with the holder's regular method of accounting for U.S. federal income tax purposes.

        A U.S. holder will generally recognize capital gain or loss on a sale, exchange, redemption, retirement, or other taxable disposition of a note measured by the difference, if any, between (i) the amount of cash and the fair market value of any property received, except to the extent that the cash or other property received in respect of a note is attributable to accrued interest on the note not previously included in income, which amount will be taxable as ordinary income, and (ii) the holder's adjusted tax basis in the note.

        Such capital gain or loss will be treated as a long-term capital gain or loss if, at the time of the sale or exchange, the note has been held by the holder for more than one year; otherwise, the capital gain or loss will be short-term. Non-corporate taxpayers may be subject to a lower federal income tax rate on their net long-term capital gains than that applicable to ordinary income. All taxpayers are subject to certain limitations on the deductibility of their capital losses.

        U.S. holders of notes may be subject, under certain circumstances, to information reporting and backup withholding (currently at a rate of 28%) on payments of interest, principal, gross proceeds from disposition of notes and, redemption premium, if any. Backup withholding generally applies only if the U.S. holder:

        Backup withholding is not an additional tax. Any amount withheld from a payment to a U.S. holder under the backup withholding rules is allowable as a credit against such U.S. holder's U.S. federal income tax liability and may entitle such holder to a refund provided such holder furnishes the required information to the Internal Revenue Service. Certain persons are exempt from backup withholding, including corporations and financial institutions. U.S. holders of notes should consult their tax advisors as to their qualification for exemption from backup withholding and the procedure for obtaining such exemption. We cannot refund amounts once withheld.

        We will furnish annually to the Internal Revenue Service, and to record holders of the notes to whom we are required to furnish such information, information relating to the amount of interest paid and the amount of backup withholding, if any, with respect to payments on the notes.

Non-U.S. Holders

        The following summary is limited to the U.S. federal income tax consequences relevant to a beneficial owner of a note who is not classified as a partnership for U.S. federal income tax purposes and who is not a U.S. holder (a "non-U.S. holder"). In the case of a non-U.S. holder who is an

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individual, the following summary assumes that this individual was not formerly a United States citizen and was not formerly a resident of the United States for U.S. federal income tax purposes.

        Subject to the summary of backup withholding rules below, payments of interest on a note to any non-U.S. holder will not generally be subject to U.S. federal income or withholding tax provided we or the person otherwise responsible for withholding U.S. federal income tax from payments on the notes receives a required certification from the non-U.S. holder and the holder is not:

        In order to satisfy the certification requirement, the non-U.S. holder must provide a properly completed Internal Revenue Service Form W-8BEN (or substitute Form W-8BEN or the appropriate successor form) under penalties of perjury that provides the non-U.S. holder's name and address and certifies that the non-U.S. holder is not a U.S. person. Alternatively, in a case where a security clearing organization, bank, or other financial institution holds the notes in the ordinary course of its trade or business on behalf of the non-U.S. holder, certification requires that we or the person who otherwise would be required to withhold U.S. federal income tax receive from the financial institution a certification under penalties of perjury that a properly completed Form W-8BEN (or substitute Form W-8BEN or the appropriate successor form) has been received by it, or by another such financial institution, from the non-U.S. holder, and a copy of such a form is furnished to the payor. Special rules apply to foreign partnerships, estates, and trusts, and in certain circumstances, certifications as to foreign status of partners, trust owners, or beneficiaries may have to be provided to our paying agent or to us. In addition, special rules apply to payments made through a qualified intermediary.

        A non-U.S. holder that does not qualify for exemption from withholding under the preceding paragraphs generally will be subject to withholding of U.S. federal income tax at the rate of 30%, or lower applicable treaty rate, on payments of interest on the notes that are not effectively connected with the conduct by the non-U.S. holder of a trade or business in the United States.

        If the payments of interest on a note are effectively connected with the conduct by a non-U.S. holder of a trade or business in the United States, such payments will be subject to U.S. federal income tax on a net basis at the rates applicable to U.S. persons generally. If the non-U.S. holder is a corporation for U.S. federal income purposes, such payments also may be subject to a 30% branch profits tax. If payments are subject to U.S. federal income tax on a net basis in accordance with the rules described in the preceding two sentences, such payments will not be subject to U.S. withholding tax so long as the holder provides us, or the person who otherwise would be required to withhold U.S. federal income tax, with the appropriate certification.

        Non-U.S. holders should consult their tax advisors regarding any applicable income tax treaties, which may provide for a lower rate of withholding tax, exemption from or reduction of branch profits tax, or other rules different from those described above.

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        Subject to the summary of backup withholding rules below, any gain realized by a non-U.S. holder on the sale, exchange, retirement, or other disposition of a note generally will not be subject to U.S. federal income tax, unless:

        Proceeds from the disposition of a note that are attributable to accrued but unpaid interest generally will be subject to, or exempt from, tax to the same extent as described above with respect to interest paid on a note, although such proceeds generally are not subject to withholding tax.

        Any payments of interest to a non-U.S. holder will generally be reported to the Internal Revenue Service and to the non-U.S. holder. Copies of these information returns also may be made available under the provisions of a specific treaty or other agreement to the tax authorities of the country in which the non-U.S. holder resides.

        The backup withholding tax and certain additional information reporting generally will not apply to payments of interest with respect to which either the requisite certification, as described above, has been received or an exemption otherwise has been established, provided that neither we nor the person who otherwise would be required to withhold U.S. federal income tax has actual knowledge or reason to know that the holder is, in fact, a U.S. person or that the conditions of any other exemption are not, in fact, satisfied.

        The payment of the proceeds from the disposition of the notes by or through the U.S. office of any broker, U.S. or foreign, will be subject to information reporting and backup withholding unless the holder certifies as to its non-U.S. status under penalties of perjury or otherwise establishes an exemption, provided that the broker does not have actual knowledge or reason to know that the holder is a U.S. person or that the conditions of any other exemption are not, in fact, satisfied. The payment of the proceeds from the disposition of the notes by or through a non-U.S. office of a non-U.S. broker will not be subject to information reporting or backup withholding unless the non-U.S. broker has certain types of relationships with the United States (a "U.S. related person"). In the case of the payment of the proceeds from the disposition of the notes by or through a non-U.S. office of a broker that is either a U.S. person or a U.S. related person, the Treasury regulations require information reporting, but not backup withholding, on the payment unless the broker has documentary evidence in its files that the owner is a non-U.S. holder and the broker has no knowledge or reason to know to the contrary.

        Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be refunded or credited against the non-U.S. holder's U.S. federal income tax liability provided such holder furnishes the required information to the Internal Revenue Service.

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UNDERWRITING

        We are offering the notes described in this prospectus supplement through a number of underwriters. ABN AMRO Incorporated, Banc of America Securities LLC, J.P. Morgan Securities Inc. and Morgan Stanley & Co. Incorporated are the representatives of the underwriters. We have entered into a firm commitment underwriting agreement with the representatives. Subject to the terms and conditions of the underwriting agreement, we have agreed to sell to the underwriters, and each underwriter has agreed to purchase, the aggregate principal amount of notes listed next to its name in the following table:

 
 Underwriter
   Principal Amount
of 20 Notes
   Principal Amount
of 20 Notes
   Principal Amount
of 20 Notes
ABN AMRO Incorporated   $     $     $  
Banc of America Securities LLC                  
J.P. Morgan Securities Inc.                  
Morgan Stanley & Co. Incorporated                  
     
 
 
  Total   $     $     $  
     
 
 

        The underwriting agreement is subject to a number of terms and conditions and provides that the underwriters must buy all of the notes if they buy any of them. The underwriters will sell the notes to the public when and if the underwriters buy the notes from us.

        The underwriters have advised us that they propose initially to offer the notes to the public for cash at the public offering prices set forth on the cover of this prospectus supplement, and to certain dealers at such price less concessions not in excess of    % of the principal amount of the 20 notes,    % of the principal amount of 20 notes and    % of the principal amount of the 20 notes. The underwriters may allow, and such dealers may reallow, a concession not in excess of    % of the principal amount of the 20 notes,     % of the principal amount of the 20 notes and    % of the principal amount of the 20 notes to certain other dealers. After the public offering of the notes, the public offering price and other selling terms may be changed.

        The aggregate proceeds to us are set forth on the cover page of this prospectus supplement before deducting our expenses in offering the notes. Abbott estimates that it will spend approximately $          million for printing, registration fees, rating agency fees and other expenses (other than estimated discounts and commissions of the underwriters) related to the offering of the notes.

        In relation to each Member State of the European Economic Area which has implemented the Prospectus Directive (each, a Relevant Member State), each underwriter has represented and agreed that with effect from and including the date on which the Prospectus Directive is implemented in that Relevant Member State (the Relevant Implementation Date) it has not made and will not make an offer of notes to the public in that Relevant Member State prior to the publication of a prospectus in relation to the notes which has been approved by the competent authority in that Relevant Member State or, where appropriate, approved in another Relevant Member State and notified to the competent authority in that Relevant Member State, all in accordance with the Prospectus Directive, except that it may, with effect from and including the Relevant Implementation Date, make an offer of notes to the public in that Relevant Member State at any time:

        (a)   to legal entities which are authorised or regulated to operate in the financial markets or, if not so authorised or regulated, whose corporate purpose is solely to invest in securities;

        (b)   to any legal entity which has two or more of (1) an average of at least 250 employees during the last financial year; (2) a total balance sheet of more than €43,000,000 and (3) an annual net turnover of more than €50,000,000, as shown in its last annual or consolidated accounts; or

S-17


        (c)   in any other circumstances which do not require the publication by the Issuer of a prospectus pursuant to Article 3 of the Prospectus Directive.

        For the purposes of this provision, the expression an "offer of notes to the public" in relation to any notes in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe the notes, as the same may be varied in that Member State by any measure implementing the Prospectus Directive in that Member State and the expression Prospectus Directive means Directive 2003/71/EC and includes any relevant implementing measure in each Relevant Member State.

        Each underwriter has represented and agreed that:

        (a)   it has only communicated or caused to be communicated and will only communicate or cause to be communicated an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the FSMA) received by it in connection with the issue or sale of the notes in circumstances in which Section 21(1) of the FSMA would not, if the Issuer was not an authorised person, apply to the Issuer; and

        (b)   it has complied and will comply with all applicable provisions of the FSMA with respect to anything done by it in relation to the notes in, from or otherwise involving the United Kingdom.

        The notes may not be offered or sold by means of any document other than to persons whose ordinary business is to buy or sell shares or debentures, whether as principal or agent, or in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap. 32) of Hong Kong, and no advertisement, invitation or document relating to the notes may be issued, whether in Hong Kong or elsewhere, which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to notes which are or are intended to be disposed of only to persons outside Hong Kong or only to "professional investors" within the meaning of the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made thereunder.

        This prospectus supplement and the accompanying prospectus have not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and the accompanying prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the notes may not be circulated or distributed, nor may the Notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the "SFA"), (ii) to a relevant person, or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

        Where the notes are subscribed or purchased under Section 275 by a relevant person which is: (a) a corporation (which is not an accredited investor) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or (b) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary is an accredited investor, shares, debentures and units of shares and debentures of that corporation or the beneficiaries' rights and interest in that trust shall not be transferable for 6 months after that corporation or that trust has acquired the notes under Section 275 except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person, or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA; (2) where no consideration is given for the transfer; or (3) by operation of law. The securities have not been and will not be registered under the Securities and Exchange Law of Japan (the Securities and Exchange Law) and each underwriter has agreed that it will not offer or sell any securities, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity

S-18


organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Securities and Exchange Law and any other applicable laws, regulations and ministerial guidelines of Japan.

        Certain of the underwriters may make the notes available for distribution on the internet through a proprietary Web site and/or a third-party system operated by MarketAxess Holdings Inc. ("MarketAxess"), an Internet-based communications technology provider. MarketAxess is providing a system as a conduit for communications between the underwriters who use MarketAxess and their respective customers and is not a party to this offering. MarketAxess, a registered broker-dealer, will receive compensation from the underwriters who use MarketAxess based on transactions they conduct through the system. The underwriters who use MarketAxess will make the notes available to their respective customers through the internet distributions, whether made through a proprietary or third-party system, on the same terms as distributions made through other channels.

        We have agreed to indemnify the underwriters against, or contribute to payments that the underwriters may be required to make in respect of, certain liabilities, including liabilities under the Securities Act of 1933.

        The notes are a new issue of securities with no established trading market. The notes will not be listed on any securities exchange or on any automated dealer quotation system. The underwriters may make a market in the notes after completion of the offering, but will not be obligated to do so and may discontinue any market-making activities at any time without notice. No assurance can be given as to the liquidity of the trading market for the notes or that an active public market for the notes will develop. If an active public market for the notes does not develop, the market price and liquidity of the notes may be adversely affected.

        In connection with the offering of the notes, the representatives may engage in transactions that stabilize, maintain or otherwise affect the price of the notes. Specifically, the representatives may overallot in connection with the offering, creating a short position. In addition, the representatives may bid for, and purchase, the notes in the open market to cover short positions or to stabilize the price of the notes. Any of these activities may stabilize or maintain the market price of the notes above independent market levels, but no representation is made hereby of the magnitude of any effect that the transactions described above may have on the market price of the notes. The representatives will not be required to engage in these activities, and may engage in these activities, and may end any of these activities, at any time without notice.

        The underwriters and certain of their affiliates have provided from time to time, and may provide in the future, investment and commercial banking and financial advisory services to us and our affiliates in the ordinary course of business, for which they have received and may continue to receive customary fees and commissions.


LEGAL OPINIONS

        Certain legal matters in connection with the offering of the notes will be passed upon for Abbott by Laura J. Schumacher, Esq., Abbott's Senior Vice President, General Counsel and Secretary, and by Mayer, Brown, Rowe & Maw LLP, Chicago, Illinois, and for the underwriters by Skadden, Arps, Slate, Meagher & Flom LLP, Chicago, Illinois. Skadden, Arps, Slate, Meagher & Flom LLP from time to time also represents Abbott in connection with other matters.

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PROSPECTUS

Abbott Laboratories

Debt Securities

        By this prospectus, Abbott may offer from time to time debt securities.

        Abbott will provide you with the specific terms and the public offering prices of these securities in supplements to this prospectus. The prospectus supplements may also add, update or change information contained in this prospectus. You should read this prospectus and the prospectus supplements carefully before you invest. This prospectus may not be used to offer and sell securities unless accompanied by a prospectus supplement.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus is dated February 28, 2006


TABLE OF CONTENTS

About this Prospectus   2
Abbott Laboratories   2
Use of Proceeds   2
Description of Debt Securities   3
Legal Opinions   11
Experts   12
Where You Can Find More Information   12


ABOUT THIS PROSPECTUS

        This prospectus is part of a registration statement that Abbott filed with the Securities and Exchange Commission under the "shelf registration" process. Under this shelf registration process, Abbott may, from time to time, sell debt securities under this prospectus. This prospectus provides you with a general description of the securities Abbott may offer. Each time Abbott sells securities, Abbott will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading "Where You Can Find More Information."


ABBOTT LABORATORIES

        Abbott Laboratories is an Illinois corporation, incorporated in 1900. Abbott's principal business is the discovery, development, manufacture and sale of a broad and diversified line of health care products.

        In 2005, Abbott had four reporting revenue segments:

        Abbott also has a 50% owned joint venture, TAP Pharmaceutical Products Inc. TAP and its subsidiary develop and market pharmaceutical products primarily for the United States and Canada.

        Abbott purchases, in the ordinary course of business, raw materials and supplies essential to Abbott's operations from numerous suppliers in the United States and abroad. Abbott markets products in approximately 130 countries through affiliates and distributors. Most of Abbott's products are sold both in the United States and internationally. Abbott employs approximately 59,735 persons in its various offices, plants and facilities located throughout the world. Abbott's corporate offices are located at 100 Abbott Park Road, Abbott Park, Illinois 60064-6400, and the telephone number is (847) 937-6100.


USE OF PROCEEDS

        Abbott will use the net proceeds from the sale of the securities for general corporate purposes.

2


DESCRIPTION OF DEBT SECURITIES

        The debt securities will be issued under an indenture between Abbott and J.P. Morgan Trust Company, National Association (as successor to Bank One Trust Company, N.A.), as trustee. The following is a summary of the material provisions of the indenture and is qualified in its entirety by the provisions of the indenture, including definitions of certain terms used in the indenture. Wherever Abbott refers to particular sections or defined terms of the indenture, those sections or defined terms are incorporated by reference in this prospectus or prospectus supplement. You should review the indenture that is incorporated by reference as an exhibit to the registration statement for additional information.

        The following summarizes certain general terms and provisions of the debt securities. Each time Abbott offers debt securities, the prospectus supplement relating to that offering will describe the terms of the debt securities Abbott is offering.

General

        Abbott may issue debt securities from time to time in one or more series without limitation as to aggregate principal amount. The debt securities will be Abbott's unsecured and unsubordinated obligations and will rank equally and ratably with Abbott's other unsecured and unsubordinated obligations.

        Unless otherwise indicated in the prospectus supplement, principal of, premium, if any, and interest on the debt securities will be payable, and the transfer of debt securities will be registrable, at any office or agency maintained by Abbott for that purpose. The debt securities will be issued only in fully registered form without coupons and, unless otherwise indicated in the applicable prospectus supplement, in denominations of $1,000 or integral multiples thereof. No service charge will be made for any registration of transfer or exchange of the debt securities, but Abbott may require you to pay a sum sufficient to cover any tax or other governmental charge imposed in connection with the transfer or exchange.

        The prospectus supplement will describe the following terms of the debt securities Abbott is offering:

3

        Abbott may offer and sell the debt securities as original issue discount securities at a substantial discount below their stated principal amount. The prospectus supplement will describe the federal income tax consequences and other special considerations applicable to original issue discount securities and any debt securities the federal tax laws treat as having been issued with original issue discount. "Original issue discount securities" means any debt security that provides for an amount less than its principal amount to be due and payable upon the declaration of acceleration of the maturity of the debt security upon the occurrence and continuation of an "Event of Default."

        The indenture does not contain covenants or other provisions designed to afford holders of the debt securities protection in the event of a highly leveraged transaction, change in credit rating or other similar occurrence.

Book-Entry Securities

        The debt securities will be represented by one or more global securities. Unless otherwise indicated in the prospectus supplement, the global security representing the debt securities will be deposited with, or on behalf of, The Depository Trust Company, New York, New York, or other successor depository Abbott appoints and registered in the name of the depository or its nominee. The debt securities will not be issued in definitive form unless otherwise provided in the prospectus supplement.

        DTC will act as securities depository for the securities. The debt securities will be issued as fully-registered securities registered in the name of Cede & Co. (DTC's partnership nominee). One fully-registered global security will be issued with respect to each $500 million of principal amount, and an additional certificate will be issued with respect to any remaining principal amount of debt securities.

4


        DTC is a limited-purpose trust company organized under the New York Banking Law, a "banking organization" within the meaning of the New York Banking Law, a member of the Federal Reserve System, a "clearing corporation" within the meaning of the New York Uniform Commercial Code, and a "clearing agency" registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934. DTC holds securities that its participants deposit with DTC. DTC also facilitates the settlement among participants of securities transactions, such as transfers and pledges, in deposited securities through electronic computerized book-entry changes in participants' accounts, thereby eliminating the need for physical movement of securities certificates. Direct participants include securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations. DTC is owned by a number of its direct participants and by the New York Stock Exchange, Inc., the American Stock Exchange, Inc. and the National Association of Securities Dealers, Inc. Access to the DTC system is also available to indirect participants such as securities brokers and dealers, banks and trust companies that clear through or maintain a custodial relationship with a direct participant, either directly or indirectly. The rules applicable to DTC and its participants are on file with the SEC. More information about DTC can be found at www.dtcc.com.

        Purchases of debt securities under the DTC system must be made by or through direct participants, which will receive a credit for the debt securities on DTC's records. The ownership interest of each actual purchaser of each debt security will be recorded on the direct and indirect participants' records. These beneficial owners will not receive written confirmation from DTC of their purchase, but beneficial owners are expected to receive a written confirmation providing details of the transaction, as well as periodic statements of their holdings, from the direct or indirect participants through which the beneficial owner entered into the transaction. Transfers of ownership interests in the debt securities are to be accomplished by entries made on the books of participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in debt securities, except in the event that use of the book-entry system for the debt securities is discontinued.

        To facilitate subsequent transfers, all debt securities deposited by participants with DTC are registered in the name of DTC's partnership nominee, Cede & Co. The deposit of debt securities with DTC and their registration in the name of Cede & Co. will not change the beneficial ownership of the debt securities. DTC has no knowledge of the actual beneficial owners of the debt securities; DTC's records reflect only the identity of the direct participants to whose accounts the debt securities are credited, which may or may not be the beneficial owners. The participants will remain responsible for keeping account of their holdings on behalf of their customers.

        Delivery of notices and other communications by DTC to direct participants, by direct participants to indirect participants, and by direct participants and indirect participants to beneficial owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time.

        Redemption notices shall be sent to DTC. If less than all of the debt securities within an issue are being redeemed, DTC's practice is to determine by lot the amount of the interest of each direct participant in such issue to be redeemed.

        Neither DTC nor Cede & Co will consent or vote with respect to debt securities unless authorized by a direct participant in accordance with DTC's procedures. Under its usual procedures, DTC mails an omnibus proxy to Abbott as soon as possible after the record date. The omnibus proxy assigns Cede & Co.'s consenting or voting rights to those direct participants to whose accounts the debt securities are credited on the record date (identified in a listing attached to the omnibus proxy).

        Principal and interest payments, if any, on the debt securities will be made to Cede & Co., as nominee of DTC. DTC's practice is to credit direct participants' accounts, upon DTC's receipt of funds and corresponding detail information from Abbott or the trustee, on the applicable payable date in

5


accordance with their respective holdings shown on DTC's records. Payments by participants to beneficial owners will be governed by standing instructions and customary practices, as is the case with securities held for the accounts of customers in bearer form or registered in "street name," and will be the responsibility of that participant and not of DTC, the trustee or Abbott, subject to any statutory or regulatory requirements as may be in effect from time to time. Payment of principal and interest to Cede & Co. is the responsibility of Abbott or the trustee. Disbursement of payments from Cede & Co. to direct participants is DTC's responsibility. Disbursement of payments to beneficial owners is the responsibility of direct and indirect participants.

        A beneficial owner must give notice through a participant to a tender agent to elect to have its debt securities purchased or tendered. The beneficial owner must deliver debt securities by causing the direct participants to transfer the participant's interest in the debt securities, on DTC's records, to a tender agent. The requirement for physical delivery of debt securities in connection with an optional tender or a mandatory purchase is satisfied when the ownership rights in the debt securities are transferred by direct participants on DTC's records and followed by a book-entry credit of tendered debt securities to the tender agent's account.

        DTC may discontinue providing its services as securities depository for the debt securities at any time by giving reasonable notice to Abbott or the trustee. Under these circumstances, if a successor securities depository is not obtained, then debt security certificates must be delivered.

        Abbott may decide to discontinue use of the system of book-entry transfers through DTC (or a successor securities depository). In that event, debt security certificates will be printed and delivered.

        The information in this section concerning DTC and DTC's book-entry system has been obtained from sources that Abbott believes to be reliable, but Abbott takes no responsibility for their accuracy.

Certain Covenants of the Company

        Restrictions on Secured Debt.    Unless otherwise provided in the prospectus supplement with respect to any series of the debt securities, if Abbott or any domestic subsidiary incurs, issues, assumes or guarantees any indebtedness for borrowed money represented by notes, bonds, debentures or other similar evidences of indebtedness and that indebtedness is secured by a mortgage, pledge or other lien on any principal domestic property or on any shares of stock or debt of any domestic subsidiary, Abbott will secure, or cause its domestic subsidiary to secure, the debt securities equally and ratably with, or prior to, that indebtedness, so long as that indebtedness is to be secured. Abbott is not required to secure the debt securities, however, if after securing such debt securities, the aggregate amount of all secured indebtedness, together with all attributable debt in respect of sale and leaseback transactions involving principal domestic properties, would not exceed 15% of Abbott's consolidated net assets. This restriction will not apply to, and there shall be excluded in computing secured indebtedness for the purpose of this restriction, indebtedness secured by:

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        The following are the meanings of terms that are important in understanding the restrictive covenants described above:


        Restrictions on Sales and Leasebacks.    Unless otherwise provided in the prospectus supplement with respect to any series of the debt securities, neither Abbott nor any domestic subsidiary may enter into any sale and leaseback transaction involving any principal domestic property, the acquisition or

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completion of construction and commencement of full operation of which has occurred more than 120 days prior thereto, unless:

Events of Default

        With respect to a series of debt securities, any one of the following events will constitute an event of default under the indenture:

        If any event of default occurs and continues, either the trustee or the holders of at least 25 percent in principal amount of the outstanding debt securities of that series may declare the principal amount or, if the debt securities of that series are original issue discount securities, the portion of the principal amount as may be specified in the terms of those debt securities, of all the debt securities of that series to be due and payable immediately by a notice in writing to Abbott, and to the trustee if given by holders. The principal amount (or specified amount) will then be immediately due and payable. After acceleration, but before a judgment or decree based on acceleration has been obtained, the holders of a majority in principal amount of outstanding debt securities of that series may, under certain circumstances, rescind and annul the acceleration.

        Additional or different events of default applicable to a series of debt securities may be described in a prospectus supplement. An event of default of one series of debt securities is not necessarily an event of default for any other series of debt securities. The prospectus supplement relating to any series of debt securities that are original issue discount securities will contain the particular provisions relating to acceleration of the stated maturity of a portion of the principal amount of that series of original issue discount securities upon the occurrence and continuation of an event of default.

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        The indenture provides that, subject to the duty of the trustee during default to act with the required standard of care, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request or direction of any of the holders, unless the holders offer the trustee reasonable security or indemnity. Generally, the holders of a majority in aggregate principal amount of the debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee.

        A holder of any series of debt securities will not have any right to institute any proceeding with respect to the indenture, or for the appointment of a receiver or trustee, or for any other remedy, unless:

However, these limitations do not apply to a suit instituted by a holder for enforcement of payment of the principal of and premium, if any, or interest on its debt securities on or after the respective due dates.

        Abbott is required to furnish to the trustee annually a statement as to its performance of certain obligations under the indenture and as to any default.

Modification and Waiver

        Abbott and the trustee may modify and amend the indenture with the consent of the holders of not less than the majority in aggregate principal amount of the outstanding debt securities of each series which is affected. Neither Abbott nor the trustee may, however, modify or amend the indenture without the consent of the holders of all debt securities affected if such action would:

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        The holders of at least a majority in principal amount of the outstanding debt securities of any series may, on behalf of all holders of that series, waive compliance by Abbott with certain restrictive provisions of the indenture. The holders of not less than a majority in principal amount of the outstanding debt securities of any series may, on behalf of all holders of that series, waive any past default under the indenture, except (1) a default in the payment of principal, premium or interest and (2) in respect of a covenant or provision of the indenture that cannot be modified or amended without the consent of those holders of each outstanding debt security of that series who were affected.

Consolidation, Merger and Sale of Assets

        Abbott may not consolidate with or merge into any other company or entity or convey, transfer or lease its properties and assets substantially as an entirety and may not permit any company or entity to merge into or consolidate with Abbott or convey, transfer or lease its properties and assets substantially as an entirety to Abbott, unless:

Defeasance and Covenant Defeasance

        The indenture provides, unless otherwise indicated in the prospectus supplement relating to that particular series of debt securities, that, at Abbott's option, Abbott:


in each case, if Abbott deposits, in trust, with the trustee money or U.S. Government Obligations, which through the payment of interest and principal in accordance with their terms will provide money, in an amount sufficient to pay all the principal of and premium, if any, and interest on the debt

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securities of that series on the dates such payments are due, which may include one or more redemption dates that Abbott designates, in accordance with the terms of the debt securities of that series.

        Abbott may establish this trust only if, among other things:


If Abbott fails to comply with its remaining obligations under the indenture after a defeasance of the indenture with respect to the debt securities of any series as described under the second item of the first sentence of this section and the debt securities of such series are declared due and payable because of the occurrence of any event of default, the amount of money and U.S. Government obligations on deposit with the trustee may be insufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. Abbott will, however, remain liable for those payments.

Concerning the Trustee

        J.P. Morgan Trust Company, National Association is trustee under the indenture. The trustee performs services for Abbott in the ordinary course of business.


LEGAL OPINIONS

        Certain legal matters in connection with the securities offered hereby will be passed upon for Abbott by Laura J. Schumacher, Esq., Abbott's Senior Vice President, General Counsel and Secretary, and by Mayer, Brown, Rowe & Maw LLP, Chicago, Illinois, and for the underwriters, dealers and agents, if any, by Skadden, Arps, Slate, Meagher & Flom LLP, Chicago, Illinois. As of February 20, 2006 Ms. Schumacher beneficially owned approximately 75,902 Abbott common shares and held options to acquire 192,739 shares, of which options to purchase 132,296 shares are currently exercisable. (These amounts include approximately 4,771 shares held for the benefit of Ms. Schumacher in the Abbott Laboratories Stock Retirement Trust pursuant to the Abbott Laboratories Stock Retirement Plan). The opinions of Ms. Schumacher, Mayer, Brown, Rowe & Maw LLP and Skadden, Arps, Slate, Meagher & Flom LLP may be conditioned upon, and may be subject to certain assumptions regarding, future action required to be taken by Abbott and any underwriter(s), dealer(s) or agent(s) in connection with

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the issuance and sale of any securities. The opinions of Ms. Schumacher, Mayer, Brown, Rowe & Maw LLP and Skadden, Arps, Slate, Meagher & Flom LLP with respect to securities may be subject to other conditions and assumptions, as indicated in the prospectus supplement. Skadden, Arps, Slate, Meagher & Flom LLP from time to time also represents Abbott in connection with certain other matters.


EXPERTS

        The Abbott Laboratories and Subsidiaries consolidated financial statements, the related financial statement schedule, and management's report on the effectiveness of internal control over financial reporting incorporated in this registration statement by reference from Abbott's Annual Report on Form 10-K for the year ended December 31, 2005 have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference, and have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

        The TAP Pharmaceutical Products, Inc. and subsidiaries consolidated financial statements and the related financial statement schedule incorporated in this registration statement by reference from Abbott's Annual Report on Form 10-K for the year ended December 31, 2005 have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference, and have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.


WHERE YOU CAN FIND MORE INFORMATION

        Abbott files annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document Abbott files with the SEC at the SEC's public reference room at 100 F Street, N.E., Washington D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the public reference room. Abbott's SEC filings are also available to the public on the SEC's web site at http://www.sec.gov. Abbott's common shares are listed on the New York Stock Exchange, the Chicago Stock Exchange and the Pacific Exchange, and information about Abbott also is available there.

        This prospectus is part of a registration statement that Abbott filed with the SEC. The SEC allows Abbott to "incorporate by reference" the information Abbott files with the SEC. This means that Abbott can disclose important information to you by referring you to other documents that Abbott identifies as part of this prospectus. The information incorporated by reference is considered to be part of this prospectus. Abbott incorporates by reference the document listed below:


Abbott also incorporates by reference any future filings it makes with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 (1) after the date of the filing of this registration statement and before its effectiveness and (2) until Abbott has terminated the offering. Abbott's subsequent filings with the SEC will automatically update and supersede information in this prospectus.

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        You may obtain a copy of these filings at no cost by writing to or telephoning Abbott at the following address and telephone number:

    Abbott Laboratories
100 Abbott Park Road
Abbott Park, Illinois 60064-6020
Attention: Laura J. Schumacher,
Senior Vice President, Secretary
and General Counsel
Phone: (847) 937-8905

        You should rely only on the information incorporated by reference or provided in this prospectus or any supplement. Abbott has not authorized anyone else to provide you with different information. This prospectus is an offer to sell or buy only the securities described in this document, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus is current and accurate only as of the date of this prospectus.

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PROSPECTUS SUPPLEMENT

May    , 2006

   
   

Joint Book-Running Managers

ABN AMRO Incorporated Banc of America Securities LLC JPMorgan   Morgan Stanley

Senior Co-Managers

Co-Managers



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TABLE OF CONTENTS
ABOUT THIS PROSPECTUS SUPPLEMENT
ABBOTT LABORATORIES
RECENT DEVELOPMENTS
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS
USE OF PROCEEDS
RATIO OF EARNINGS TO FIXED CHARGES
CAPITALIZATION
DESCRIPTION OF NOTES
MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS
UNDERWRITING
LEGAL OPINIONS
TABLE OF CONTENTS
ABOUT THIS PROSPECTUS
ABBOTT LABORATORIES
USE OF PROCEEDS
DESCRIPTION OF DEBT SECURITIES
LEGAL OPINIONS
EXPERTS
WHERE YOU CAN FIND MORE INFORMATION