View:
Download DOC
Download PDF
Download XLS
Prepared by MERRILL CORPORATION
QuickLinks -- Click here to rapidly navigate through this document

Prospectus Supplement to Prospectus dated June 28, 2001.

$3,250,000,000

Abbott Laboratories

$1,650,000,000
5.125% Notes due July 1, 2004
$1,600,000,000
5.625% Notes due July 1, 2006

     Abbott will pay interest on the Notes on January 1 and July 1 of each year. The first such payment will be made on January 1, 2002. The Notes will be issued only in denominations of $1,000 and integral multiples of $1,000.

    Abbott has the option to redeem, at any time, all or a portion of the Notes at a redemption price equal to the sum of (1) the principal amount of the Notes to be redeemed, plus accrued interest to the redemption date, and (2) a Make-Whole Amount. See "Description of Notes—Redemption of the Notes."

    Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed on the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

 
   Per Note
   
   Per Note
   
 
   due 2004
   Total
   due 2006
   Total
Initial public offering price   99.831%   $ 1,647,211,500   99.671%   $ 1,594,736,000
Underwriting discount   0.450%   $ 7,425,000   0.600%   $ 9,600,000
Proceeds, before expenses, to Abbott   99.381%   $ 1,639,786,500   99.071%   $ 1,585,136,000

    The initial public offering price set forth above does not include accrued interest, if any. Interest on the Notes will accrue from July 5, 2001 and must be paid by the purchaser if the Notes are delivered after July 5, 2001.

    The underwriters expect to deliver the Notes in book-entry form only through the facilities of The Depository Trust Company against payment in New York, New York on July 5, 2001.

Joint Book-Running Managers

Banc of America Securities LLC Goldman, Sachs & Co. Salomon Smith Barney
Banc One Capital Markets, Inc. Morgan Stanley ABN AMRO Incorporated
BMO Nesbitt Burns Corp. First Union Securities, Inc. ING Barings
SG Cowen Wachovia Securities, Inc. The Williams Capital Group, L.P.

Prospectus Supplement dated June 28, 2001.


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 and services.

    Abbott has five reporting revenue segments: Pharmaceutical Products, Diagnostic Products, Hospital Products, Ross Products, and International. Abbott also has a 50 percent owned joint venture, TAP Pharmaceutical Products Inc. On March 2, 2001, Abbott completed its acquisition of the pharmaceutical business of BASF, which includes the global pharmaceutical operations of Knoll, for $6.9 billion in cash. Abbott funded the acquisition by using $650 million of existing cash and $6.25 billion of the proceeds from the issuance of commercial paper. See "Use of Proceeds" and "Capitalization." The acquisition complements the product and development portfolio of Abbott's core franchises, including cancer, cardiovascular, neuroscience/pain, and metabolic diseases.

    Abbott is integrating the commercial and manufacturing operations of BASF's pharmaceutical business in the United States into the Pharmaceutical Products Division, and outside the United States into the International Division. All of the research and development operations are a part of Abbott's global pharmaceutical research and development organization.

Pharmaceutical Products

    The Pharmaceutical Products segment includes a broad line of adult and pediatric pharmaceuticals which are sold primarily on the prescription or recommendation of physicians.

    The principal products included in the Pharmaceutical Products segment are:

In addition, the Pharmaceutical Products segment co-promotes the proton pump inhibitor Prevacid® (lansoprazole) for short-term treatment of duodenal ulcers, gastric ulcers and erosive esophagitis under an agreement with TAP Pharmaceuticals Inc.

    The Pharmaceutical Products segment markets its products in the United States and generally sells its products directly to wholesalers, government agencies, health care facilities, and independent retailers from Abbott-owned distribution centers and public warehouses. This segment directs its primary marketing efforts for pharmaceutical products toward securing the prescription of Abbott's brand of products by physicians. Managed care purchasers (for example, health maintenance organizations and pharmacy benefit managers) are increasingly important customers.

S–1

Diagnostic Products

    The Diagnostic Products segment includes diagnostic systems and tests for blood banks, hospitals, reference laboratories, alternate-care testing sites and consumers.

    The principal products included in the Diagnostic Products segment are:

In addition, the Diagnostic Products segment distributes the i-STAT® point-of-care testing system through an exclusive worldwide sales and marketing alliance with i-STAT Corporation.

    The Diagnostic Products segment markets its products worldwide. It generally markets and sells its products directly to hospitals, laboratories, clinics and physicians' offices from Abbott-owned distribution centers and public warehouses. Outside the United States, this segment makes sales either directly to customers or through distributors, depending on the market served. The Diagnostic Products segment also sells blood glucose monitoring meters and test strips for people with diabetes over the counter to consumers. Some of the products in this segment are subject to restrictions on their sale in the United States.

    On November 4, 1999, a consent decree was entered in the United States District Court for the Northern District of Illinois which settled issues with the United States government involving alleged noncompliance with the FDA's Quality System Regulation at Abbott's diagnostic manufacturing operations in Lake County, Illinois. The consent decree does not represent an admission by Abbott of any violation of the Federal Food, Drug and Cosmetic Act or its regulations. The decree allows for the continued manufacture and distribution of medically necessary diagnostic products made in Lake County, Illinois, such as certain assays for hepatitis, retrovirus, cardiovascular disease, cancer, thyroid disorders, fertility, drug monitoring, and congenital and respiratory conditions. However, Abbott is prohibited from manufacturing or distributing certain other diagnostic products until Abbott ensures the processes in its Lake County, Illinois diagnostics manufacturing operations conform

S–2

with the current Quality System Regulation. Under the terms of the consent decree, among other actions, Abbott has submitted to the FDA proposed master compliance and validation plans to ensure its processes conform with the current Quality System Regulation. Originally, the decree required Abbott to ensure its facilities are in conformance with the current Quality System Regulation by November 3, 2000. However, on December 19, 2000, upon a joint motion by Abbott and the U.S. government, the Court entered an amended consent decree. Under the terms of the amended consent decree, Abbott must ensure its diagnostics manufacturing operations are in conformance with the Quality System Regulation by various dates through January 15, 2001. The FDA will determine Abbott's conformance with the Quality System Regulation after an inspection of Abbott's facilities. If the FDA concludes that the operations are not in conformance with the Quality System Regulation as of the date required, Abbott may be subject to additional costs. The consent decree allows Abbott to export diagnostic products and components for sale and distribution outside the United States if they meet the export requirements of the Federal Food, Drug and Cosmetic Act.

Hospital Products

    The Hospital Products segment includes drugs and drug delivery systems, perioperative and intensive care products, cardiovascular products, renal products, oncology products, intravenous and irrigation solutions, related manual and electronic administration equipment, and diagnostic imaging products for hospitals and alternate-care sites.

    The principal products included in the Hospital Products segment are:

S–3

    The Hospital Products segment markets its products primarily in the United States and generally distributes them to wholesalers and directly to hospitals from Abbott-owned distribution centers and public warehouses. The Hospital Products segment also develops and manufactures products for other companies.

Ross Products

    The Ross Products segment includes a broad line of adult and pediatric nutritionals. The Ross Products segment sells these products primarily on the recommendation of physicians or other health care professionals. This segment also includes specialty pharmaceuticals and self-care consumer products.

    Principal products in the Ross Products segment include:

In addition, the Ross Products segment co-promotes Synagis® under an agreement with MedImmune Incorporated.

    The Ross Products segment markets its products in the United States and generally sells nutritional products directly to retailers, wholesalers, health care facilities and government agencies. In most cases, they are distributed from Abbott-owned distribution centers or public warehouses. This segment directs its primary marketing efforts for nutritional products toward securing the recommendation of Abbott's brand of products by physicians or other health care professionals.

    The Ross Products segment generally markets and sells its pharmaceutical products directly to physicians, retailers, wholesalers, health care facilities and government agencies. In most cases, they are distributed from Abbott-owned distribution centers or public warehouses. This segment directs its primary marketing efforts for pharmaceutical products toward securing the prescription of these products by physicians.

    The Ross Products segment promotes consumer products and PediaSure®, Pedialyte® and Ensure® retail products directly to the public by consumer advertising. It generally sells these products directly to retailers and wholesalers.

    Ensure® is the leading adult nutritional supplement, and Similac® and Isomil® are leading infant formulas, in the United States. (Source: A. C. Nielsen Co.)

International

    The International segment includes a broad line of hospital, pharmaceutical and adult and pediatric nutritional products marketed and primarily manufactured outside the United States. This

S–4

segment sells these products primarily on the prescription or recommendation of physicians and other health care professionals. This segment also includes consumer products.

    The International segment's principal products include:

    The International segment generally sells pharmaceutical and nutritional products directly to government agencies, retailers, wholesalers and health care facilities. In most cases, they are distributed from Abbott-owned distribution centers. Some products are co-marketed with other companies and are marketed and distributed through distributors. This segment directs its primary marketing efforts for pharmaceutical products toward securing the prescription of Abbott's brand of products by physicians. It directs its primary marketing efforts for nutritional products toward securing the recommendation of Abbott's brand of products by physicians or other health care professionals.

    The International segment generally distributes hospital products to wholesalers and directly to hospitals from distribution centers maintained by Abbott.

S–5

TAP Pharmaceutical Products Inc.

    Under an agreement between Abbott and Takeda Chemical Industries, Ltd. 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 for the United States and Canada. TAP markets Lupron®, an LH-RH analog, and Lupron Depot®, a sustained release form of Lupron®, in the United States. Lupron® and Lupron Depot® are used principally for the palliative treatment of advanced prostate cancer and for the treatment of endometriosis and central precocious puberty and for the preoperative treatment of patients with anemia caused by uterine fibroids. TAP also markets Prevacid® (lansoprazole), a proton pump inhibitor, and has a co-promotion arrangement with Abbott for Prevacid®. Its principal indications are for short-term treatment of duodenal ulcers, gastric ulcers, and erosive esophagitis.

    TAP generally sells its products directly to physicians, retailers, wholesalers, health care facilities, and government agencies. In most cases, they are distributed from Abbott-owned distribution centers. TAP directs its primary marketing efforts for pharmaceutical products toward securing the prescription of TAP's brand of products by physicians. Managed care purchasers (for example, health maintenance organizations and pharmacy benefit managers) are increasingly important customers.

    The U.S. Department of Justice is investigating the marketing and sales practices of TAP for Lupron® during the 1990s. Abbott has established a litigation reserve reflecting its best estimate of potential losses arising out of the investigation. While it is not feasible to predict the outcome of this matter with certainty, management is of the opinion that its ultimate disposition should not have a material adverse effect on Abbott's financial position, results of operations or cash flows.

Competition

    Competition in the Pharmaceutical Products segment generally comes from other broad line pharmaceutical companies. The search for technological innovations in pharmaceutical products is a significant aspect of competition in this segment. The introduction of new products by competitors and changes in medical practices and procedures can result in product obsolescence in the Pharmaceutical Products segment. Price can also be a factor. In addition, the substitution of generic drugs for the brand prescribed has increased competitive pressures on pharmaceutical products which are off-patent.

    Products in the Diagnostic Products segment are generally subject to competition in technological innovation, price, convenience of use, service, instrument warranty provisions, product performance, long-term supply contracts, and product potential for overall cost-effectiveness and productivity gains. Some products in this segment can become rapidly obsolete. Abbott has benefited from technological advantages of some of its current products in the Diagnostic Products segment. As competitors introduce new products in this segment, these advantages may, however, be reduced or eliminated.

    Products in the Hospital Products segment are generally subject to competition in technological innovation, price, convenience of use, service, instrument warranty provisions, product performance, long-term supply contracts, and product potential for overall cost-effectiveness and productivity gains. Some products in this segment can become rapidly obsolete. Abbott has benefited from technological advantages of some of its current products in the Hospital Products segment. As competitors introduce new products in this segment, these advantages may, however, be reduced or eliminated.

S–6

    Competition for nutritional products in the Ross Products segment generally comes from other broad line and specialized health care manufacturers. Nutritional products are subject to competition in price, formulation, scientific innovation and promotional initiatives. Competition for pharmaceutical products in the Ross Products segment generally comes from other broad line pharmaceutical companies. The search for technological innovations in pharmaceutical products is a significant aspect of competition in this segment. The introduction of new pharmaceutical products by competitors and changes in medical practices and procedures can result in product obsolescence. Price can also be a factor. In addition, the substitution of generic drugs for the brand prescribed has increased competitive pressures on pharmaceutical products which are off-patent. Competition for consumer products and PediaSure®, Pedialyte® and Ensure® retail products in the Ross Products segment comes from diversified consumer and health care companies. Competitive factors include consumer advertising, formulation, scientific innovation, price and availability of generic product forms.

    Competition for pharmaceutical products in the International segment generally comes from other broad line and specialized pharmaceutical companies. The search for technological innovation in pharmaceutical products is a significant aspect of competition in this segment. The introduction of new pharmaceutical products by competitors and changes in medical practices and procedures can result in product obsolescence in the International segment. Price can also be a factor. In addition, the substitution of generic drugs for the brand prescribed has increased competitive pressures on pharmaceutical products. Competition for nutritional products in the International segment generally comes from other broad line and specialized health care manufacturers and food companies. Nutritional products are subject to competition in price, scientific innovation, formulation, and promotional initiatives. Hospital products in the International segment are subject to competition in technological innovation, price, convenience of use, instrument warranty provisions, service, product performance, long-term supply contracts, and product potential for overall cost effectiveness and productivity gains. Hospital products can become rapidly obsolete. Abbott has benefited from the technological advantages of some of its current hospital products in the International segment. As competitors introduce new hospital products, these advantages may, however, be reduced or eliminated.

    Competition for TAP's products generally comes from other pharmaceutical companies. The search for technological innovations in pharmaceutical products is a significant aspect of competition. The introduction of new pharmaceutical products by competitors and changes in medical practices and procedures can result in obsolescence of TAP's pharmaceutical products. Price can also be a factor. In addition, the substitution of generic drugs for the brand prescribed has increased competitive pressures on pharmaceutical products which are off-patent.


FORWARD-LOOKING STATEMENTS

    This prospectus supplement and the accompanying prospectus include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. You can identify some of the forward-looking words, such as "should," "believes," "expects," "may," "will," "approximately," "intends," "plans," "estimates," or "anticipates," or the negative of those words or other similar words. Forward-looking statements involve inherent risks and uncertainties. Important factors that could cause actual results to differ materially from estimates or projections contained in the forward-looking statements include, without limitation:

S–7

    In light of these risks, uncertainties and assumptions, the events anticipated by Abbott's forward-looking statements might not occur. For those statements, Abbott claims the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Abbott does not take any responsibility to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.


USE OF PROCEEDS

    Abbott will use the net proceeds from the sale of the Notes to repay commercial paper indebtedness incurred to partially fund the acquisition of the pharmaceutical business of BASF. See "Abbott Laboratories." The indebtedness to be repaid is of varying maturities of less than one year. As of June 22, 2001, Abbott's outstanding principal balance of commercial paper was approximately $6.4 billion, at a weighted average interest rate of 4.0%.

S–8


CAPITALIZATION

    The following table sets forth Abbott's consolidated capitalization (1) at March 31, 2001 and (2) as adjusted to give effect to the offering and the application of the net proceeds from the offering. See "Use of Proceeds."

 
   At March 31, 2001
 
   Actual
   As Adjusted
 
   (In Millions)
Short term debt:            
  Commercial paper   $ 5,691   $ 2,468
  Other     276     276
   
 
    Total short term debt   $ 5,967   $ 2,744
   
 
Long term debt:            
  5.125% Notes due 2004   $ —   $ 1,650
  5.625% Notes due 2006     —     1,600
  5.6% Notes due 2003     200     200
  6.8% Notes due 2005     150     150
  6.4% Notes due 2006     250     250
  6.0% Notes due 2008     200     200
  5.4% Notes due 2008     200     200
  Other     76     76
   
 
    Total long term debt   $ 1,076   $ 4,326
   
 
Total shareholders' investment   $ 8,099   $ 8,099
   
 
    Total capitalization   $ 9,175   $ 12,425
   
 

S–9


RATIO OF EARNINGS TO FIXED CHARGES

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

 
   Year Ended December 31,
   Pro Forma
Year Ended
December 31,
   Quarter Ended March 31,
   Pro Forma
Quarter Ended
March 31,
 
   1996
   1997
   1998
   1999
   2000
   2000
   2000
   2001
   2001
Ratio of earnings to fixed charges   20.4   17.5   16.2   17.9   22.2   12.4   23.6   *   *
*
Deficiencies in earnings to cover fixed charges were $387.0 million for the quarter ended March 31, 2001 on an actual basis and $401.0 million on a pro forma basis. The ratio of earnings to fixed charges would have been 15.5 on an actual basis and 12.8 on a pro forma basis, excluding a charge of $1.015 billion for acquired in-process research and development related to the acquisition of the pharmaceutical business of BASF and an increase of $344.0 million in a litigation reserve related to the U.S. Department of Justice investigation of TAP's marketing and sales practices relating to Lupron®.

    For purposes of calculating the ratio of earnings to fixed charges, earnings have been calculated by adjusting net earnings for taxes on earnings, interest expense, capitalized interest cost (net of amortization), 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 the increased interest expense from the issuance of the Notes due 2004 based on an actual interest rate of 5.125% per annum and the issuance of the Notes due 2006 based on an actual interest rate of 5.625% per annum, and the reduction of interest expense resulting from any outstanding commercial paper during the pro forma period noted above. For the year ended December 31, 2000, the pro forma computation reflects the repayment of a monthly average of approximately $477 million of commercial paper. For the quarter ended March 31, 2001, the pro forma computation reflects the repayment of a portion of the commercial paper indebtedness incurred on March 2, 2001 to partially fund the acquisition of the pharmaceutical business of BASF. This amount may not be indicative of actual commercial paper outstanding after application of the net proceeds of the offering to repay a portion of the commercial paper. See "Use of Proceeds."

S–10


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 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.

Titles

    5.125% Notes due July 1, 2004 (the "Notes due 2004") and 5.625% Notes due July 1, 2006 (the "Notes due 2006" and, together with the Notes due 2004, the "Notes").

    General:  Abbott will issue the Notes as two separate series of debt securities under an indenture (the "Indenture"), dated as of February 9, 2001, between Abbott and 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 attached prospectus.

    Abbott may, without the consent of the holders, increase the aggregate principal amount of the Notes due 2004 and the Notes due 2006 in the future. Any additional Notes due 2004 and Notes due 2006 will have the same ranking, interest rate, maturity date and other terms as the Notes due 2004 and the Notes due 2006, respectively, being offered by this prospectus supplement. Any additional Notes due 2004 and Notes due 2006, together with the Notes due 2004 and Notes due 2006, respectively, offered by this prospectus supplement, will each constitute a single series of debt securities under the Indenture.

    Form:  Abbott will issue the Notes only in book-entry form through the facilities of The Depository Trust Company ("DTC"), and sales in book-entry form may be effected only through a participating member of DTC. See "Global Securities" below.

Total Principal Amount of Notes

    $1,650,000,000 of Notes due 2004 and $1,600,000,000 of Notes due 2006.

Maturity of Notes

    The Notes due 2004 will mature on July 1, 2004, and the Notes due 2006 will mature
on July 1, 2006.

Interest Rate on Notes

    The interest rates on the Notes due 2004 and Notes due 2006 are 5.125% per annum and 5.625% per annum, respectively, in each case computed on the basis of a 360-day year of twelve 30-day months.

Date Interest Begins to Accrue on Notes

    Interest will begin to accrue on the Notes due 2004 and Notes due 2006 on July 5, 2001.

S–11

Interest Payment Date

    Abbott will pay interest on the Notes due 2004 and the Notes due 2006 semi-annually on each January 1 and July 1 (each an "Interest Payment Date"). Interest payable on each Interest Payment Date will include interest accrued from July 5, 2001 or from the most recent Interest Payment Date to which interest has been paid or duly provided for.

First Interest Payment Date

    January 1, 2002.

Regular Record Dates for Interest

    Abbott will pay interest payable on any Interest Payment Date to the person in whose name a Note due 2004 or Note due 2006 (or any predecessor note) is registered at the close of business on December 15 or June 15, 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 due 2004 and Notes due 2006 will each be represented by one or more global securities registered in the name of the nominee of DTC. Abbott will issue the Notes in denominations of $1,000 and integral multiples of $1,000. 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 attached prospectus.

Redemption of the Notes

    The Notes due 2004 and Notes due 2006 may be redeemed at any time at Abbott's option, in whole or from time to time in part, at a redemption price equal to the sum of (1) the principal amount of any Notes due 2004 and Notes due 2006 being redeemed plus accrued interest to the redemption date and (2) the Make-Whole Amount (as defined below), if any.

    If Abbott has given notice as provided in the Indenture and funds for the redemption of any Notes due 2004 and Notes due 2006 called for redemption have been made available on the redemption date, such Notes due 2004 and Notes due 2006 will cease to bear interest on the date fixed for redemption. Thereafter, the only right of the holders of such Notes due 2004 and Notes due 2006 will be to receive payment of the redemption price.

    Abbott will give notice of any optional redemption to holders at their addresses, as shown in the security register for such Notes due 2004 and Notes due 2006, not more than 60 nor less than 30 days prior to the date fixed for redemption. The notice of redemption will specify, among other items, the redemption price and the principal amount of the Notes due 2004 and Notes due 2006 held by such holder to be redeemed.

    Abbott will notify the Trustee at least 45 days prior to giving notice of redemption (or such shorter period as is satisfactory to the Trustee) of the aggregate principal amount of Notes due 2004 and Notes due 2006 to be redeemed and their redemption date. If less than all of the Notes due 2004 and Notes due 2006 are to be redeemed, the Trustee shall select which Notes due 2004 and Notes due 2006 are to be redeemed in a manner it deems to be fair and appropriate.

S–12

    As used above:

    "Make-Whole Amount" means the excess of (1) the aggregate present value, on the redemption date, of the principal being redeemed or paid and the amount of interest (exclusive of interest accrued to the date of redemption or accelerated payment) that would have been payable if such redemption or accelerated payment had not been made, over (2) the aggregate principal amount of the Notes due 2004 and Notes due 2006 being redeemed or paid. Net present value shall be determined by discounting, on a semi-annual basis, such principal and interest at the Reinvestment Rate (as defined below and as determined on the third business day preceding the date such notice of redemption is given or declaration of acceleration is made) from the respective dates on which such principal and interest would have been payable if such redemption or accelerated payment had not been made.

    "Reinvestment Rate" for the Notes due 2004 and the Notes due 2006 means 0.10% and 0.125%, respectively, plus the arithmetic mean of the yields under the respective heading "Week Ending" published in the most recent Statistical Release (as defined below) under the caption "Treasury Constant Maturities" for the maturity (rounded to the nearest month) corresponding to the remaining life to maturity, as of the payment date of the principal being redeemed or paid. If no maturity exactly corresponds to such maturity, yields for the two published maturities most closely corresponding to such maturity shall be calculated pursuant to the immediately preceding sentence and the Reinvestment Rate shall be interpolated or extrapolated from such yields on a straight-line basis, rounding in each of such relevant periods to the nearest month. For the purpose of calculating the Reinvestment Rate, the most recent Statistical Release published prior to the date of determination of the Make-Whole Amount shall be used.

    "Statistical Release" means the statistical release designated "H.15(519)" or any successor publication which is published weekly by the Federal Reserve System and which establishes yields on actively traded United States government securities adjusted to constant maturities, or, if such statistical release is not published at the time of any determination under the Indenture, then such other reasonably comparable index which shall be designated by Abbott.

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.

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 attached 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:

S–13

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 due 2004 and Notes due 2006 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 due 2004 and Notes due 2006 are represented by the global securities registered in the name of DTC or its nominee, the Notes due 2004 and Notes due 2006 will trade in DTC's Same-Day Funds Settlement System. DTC will require secondary market trading activity in the Notes due 2004 and Notes due 2006 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 due 2004 and Notes due 2006.

    This section summarizes the specific financial and legal terms of the Notes that are more generally described under "Description of Debt Securities" in the attached prospectus. If anything described in this section is inconsistent with the terms described under "Description of Debt Securities" in the attached prospectus, you should consider the terms here to be the ones that prevail.

S–14


UNDERWRITING

    Abbott and the underwriters for the offering (the "Underwriters") named below have entered into an underwriting agreement and a pricing agreement with respect to the Notes. Subject to certain conditions, each Underwriter has severally agreed to purchase the principal amount of Notes indicated in the following table.

           Underwriter         
  Principal
Amount of
Notes due 2004
   Principal
Amount of
Notes due 2006
Banc of America Securities LLC.   $ 445,500,000   $ 432,000,000
Goldman, Sachs & Co.     445,500,000     432,000,000
Salomon Smith Barney Inc.     445,500,000     432,000,000
Banc One Capital Markets, Inc.     165,000,000     160,000,000
Morgan Stanley & Co. Incorporated     45,375,000     44,000,000
ABN AMRO Incorporated     16,500,000     16,000,000
BMO Nesbitt Burns Corp.     16,500,000     16,000,000
First Union Securities, Inc.     16,500,000     16,000,000
ING Barings LLC     16,500,000     16,000,000
SG Cowen Securities Corporation     16,500,000     16,000,000
Wachovia Securities, Inc.     16,500,000     16,000,000
The Williams Capital Group, L.P.     4,125,000     4,000,000
   
 
  Total   $ 1,650,000,000   $ 1,600,000,000
   
 

    Notes due 2004 and Notes due 2006 sold by the Underwriters to the public will initially be offered at the initial public offering price set forth on the cover of this prospectus. Any Notes due 2004 and Notes due 2006 sold by the Underwriters to securities dealers may be sold at a discount from the initial public offering price of up to 0.25% and 0.35% of the principal amount of the Notes due 2004 and Notes due 2006, respectively. Any such securities dealers may resell any Notes due 2004 and Notes due 2006 purchased from the Underwriters to certain other brokers or dealers at a discount from the initial public offering price of up to 0.20% and 0.25% of the principal amount of the Notes due 2004 and Notes due 2006, respectively. If all the Notes due 2004 and Notes due 2006 are not sold at the initial public offering price, the Underwriters may change the offering price and the other selling terms.

    The Notes due 2004 and Notes due 2006 are new issues of securities with no established trading market. Abbott has been advised by the Underwriters that the Underwriters intend to make a market in the Notes due 2004 and Notes due 2006 but are not obligated to do so and may discontinue market making at any time without notice. No assurance can be given as to the liquidity of the trading market for the Notes due 2004 and Notes due 2006.

    In connection with the offering, the Underwriters may purchase and sell Notes in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the Underwriters of a greater number of Notes than they are required to purchase in the offering. Stabilizing transactions consist of certain bids or purchases made for the purpose of preventing or retarding a decline in the market price of the Notes while the offering is in progress.

    The Underwriters also may impose a penalty bid. This occurs when a particular Underwriter repays to the Underwriters a portion of the underwriting discount received by it because the representatives have repurchased Notes sold by or for the account of such Underwriter in stabilizing or short covering transactions.

S–15

    These activities by the Underwriters may stabilize, maintain or otherwise affect the market price of the Notes. As a result, the price of the Notes may be higher than the price that otherwise might exist in the open market. If these activities are commenced, they may be discontinued by the Underwriters at any time. These transactions may be effected in the over-the-counter market or otherwise.

    Bank One Trust Company, N.A., the trustee, is an affiliate of Banc One Capital Markets, Inc.

    Abbott estimates that its share of the total expenses of the offering, excluding underwriting discounts and commissions, will be approximately $1,500,000.

    Abbott has agreed to indemnify the several Underwriters against certain liabilities, including liabilities under the Securities Act of 1933.


LEGAL OPINIONS

    Certain legal matters in connection with the offering of the Notes will be passed upon for Abbott by Jose M. de Lasa, Esq., Abbott's Senior Vice President, General Counsel and Secretary, and by Mayer, Brown & Platt, Chicago, Illinois, and for the Underwriters by Skadden, Arps, Slate, Meagher & Flom (Illinois), Chicago, Illinois. Skadden, Arps, Slate, Meagher & Flom (Illinois) and its affiliates from time to time also represent Abbott in connection with other matters.

S–16

PROSPECTUS

Abbott Laboratories

    By this prospectus, Abbott may offer from time to time a total of up to $3,500,000,000 of common shares and debt securities, which may include up to:

                               —$268,125,000 of common shares
                               —$3,500,000,000 of debt securities

    Abbott will provide you with the specific terms and the public offering prices of these securities in supplements to 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 June 28, 2001



ABOUT THIS PROSPECTUS

    This prospectus is part of a registration statement that Abbott filed with the Securities and Exchange Commission under the shelf process. Abbott may sell common shares for up to $268,125,000 and debt securities for up to $3,500,000,000 under this prospectus, but the total sales of all securities sold under this prospectus may not exceed $3,500,000,000. 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 and services.

    Abbott has five revenue segments:

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

    Abbott purchases, in the ordinary course of business, necessary raw materials and supplies essential to Abbott's operations from numerous suppliers worldwide. 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 60,600 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 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 filed 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 which 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.

4

    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 $400 million of principal amount, and an additional certificate will be issued with respect to any remaining principal amount of debt securities.

    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.

    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. 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

5

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 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:

6

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


7

    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 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 aggregate 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

8

immediately due and payable. After acceleration, but before a judgment or decree based on acceleration has been obtained, the holders of a majority in aggregate principal amount of outstanding debt securities of that series may, under certain circumstances, rescind and annul the acceleration.

    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.

    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 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 their debt security 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:

9

    The holders of at least a majority in aggregate 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 aggregate 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:

10

    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 preceding sentence 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

    Bank One Trust Company, N.A. is trustee under the indenture. The trustee performs services for Abbott in the ordinary course of business.

11


DESCRIPTION OF COMMON SHARES

Authorized and Outstanding

    As of March 31, 2001, Abbott had 2,400,000,000 authorized common shares, of which 1,548,255,388 were outstanding, and 1,000,000 authorized preferred shares, of which none were outstanding. Abbott's board of directors determines the terms and the manner in which the preferred shares may be issued.

Listing

    Abbott's common shares are listed on the New York, Chicago, Pacific and London exchanges, as well as the Swiss stock exchange. They are traded on the Boston, Cincinnati and Philadelphia exchanges. The ticker symbol for Abbott's common shares is ABT.

Dividends

    The board of directors may authorize, and Abbott may make, distributions to its common shareholders, subject to any restriction in Abbott's articles of incorporation and to those limitations prescribed by law.

Fully Paid

    All of Abbott's outstanding common shares are fully paid and non-assessable. Any additional common shares that Abbott issues will be fully paid and non-assessable.

Voting Rights

    Each of Abbott's outstanding common shares is entitled to one vote in each matter submitted to a vote at a meeting of shareholders. In addition, in all elections for directors, every shareholder has the right to vote the number of shares owned by it for as many persons as there are directors to be elected, or to cumulate its votes and give one candidate as many votes as shall equal the number of directors multiplied by the number of shares or to distribute its cumulative votes in any proportion among any number of candidates. Abbott's shareholders may vote either in person or by proxy.

Shareholder Action by Written Consent; Meetings

    Under Illinois corporate law, any action required to be taken by Abbott's shareholders may be taken without a meeting and without a vote if a consent in writing is signed by holders of shares having at least the number of votes necessary at a shareholder meeting.

    Abbott's by-laws provide that special meetings of the shareholders of the corporation may be called only by:

12

Transfer Agent and Registrar

    BankBoston, N.A. is Abbott's transfer agent and registrar. BankBoston is located in Boston, Massachusetts.

Shareholder Rights Plan

    On November 10, 1999, the Abbott board of directors declared a dividend distribution of one right for each outstanding common share of Abbott to shareholders of record at the close of business on December 1, 1999, the record date. Except as described below, each right, when exercisable, entitles the registered holder to purchase from Abbott one ten-thousandth of a share of series A junior participating preferred stock, par value $1.00 per share, at a purchase price of $200 for each one ten-thousandth of a share, subject to adjustment.

    Initially, the rights automatically attached to all common share certificates representing shares then outstanding, and no separate certificates evidencing the rights were distributed. Rights will be attached to all shares of common stock issued in the future prior to the termination of the rights agreement. The rights will be evidenced by the common share certificates and not by separate certificates until the earlier to occur of:

The earlier of these two dates is referred to in the rights agreement as the distribution date.

    Until the distribution date, the rights will be transferred only with the Abbott common shares. As soon as practicable following the distribution date, right certificates will be mailed to holders of record of the Abbott common shares as of the close of business on the distribution date. After the distribution date, the separate right certificates will evidence the rights. Any Abbott common shares issued after the distribution date will generally be accompanied by right certificates only if such Abbott common shares are issued pursuant to the exercise of options or under any employee plan or arrangement or upon the exercise, conversion or exchange of other securities issued by Abbott, or if the issuance of accompanying right certificates is deemed necessary or appropriate by the Abbott board of directors.

    The rights are not exercisable until the distribution date and will expire at the earliest of:

    If any person, other than Abbott, its affiliates or any person receiving newly-issued common shares directly from Abbott, becomes the beneficial owner of 10% or more of the then outstanding common shares, each rightsholder will have the right to receive, upon exercise at the then current exercise price of the right, common shares, or, in certain circumstances, cash, property or other securities of Abbott, having a value equal to two times the exercise price of the right.

    If, after an acquiring person obtains 10% or more of the outstanding Abbott common shares, Abbott is acquired in a merger or other business combination transaction or 50% or more of

13

Abbott's assets or earning power are sold, each holder of a right will have the right to receive, upon exercise at the then current exercise price of the right, common stock of the acquiring or surviving company having a value equal to two times the exercise price of the right.

    Following the occurrence of any of the events set forth in the preceding two paragraphs, any rights that are, or, under certain circumstances specified in the rights agreement, were, beneficially owned by any acquiring person will immediately become null and void.

    At any time after the acquisition by a person or group of affiliated or associated persons of beneficial ownership of 10% or more of the outstanding common shares and prior to the acquisition by that person or group of 50% or more of the outstanding common shares or the existence of a solicitation participant, the board of directors may exchange the rights, other than rights owned by that person or group, which have become void, in whole or in part, at an exchange ratio of one common share for each right, subject to adjustment.

    Subject to the following paragraph, at any time after the date of the rights agreement until the earlier of the time that a person becomes an acquiring person or November 10, 2009, the Abbott board of directors may redeem the rights in whole, but not in part, at a price of $.0001 for each right, which may, at the option of Abbott be paid in cash, common shares or other consideration deemed appropriate by the board. Upon the effectiveness of any action of the board ordering redemption of the rights, the rights will terminate, leaving the rightsholders with only the right to receive this redemption price.

    If at any time prior to a person becoming an acquiring person:

then the approval by holders of at least 85% of the outstanding common shares, known as the shareholder approval, would be required prior to any redemption of the rights or any amendment of the rights agreement that would adversely affect the interests of rightsholders or facilitate a transaction with a solicitation participant.

    The rights have certain anti-takeover effects. The rights will cause substantial dilution to a person or group that attempts to acquire Abbott without conditioning the offer on the rights being redeemed or a substantial number of rights being acquired, and under certain circumstances the rights beneficially owned by that person or group may become void. The rights should not interfere with any merger or other business combination approved by the board of directors because the board may, at its option subject to shareholder approval, if applicable, at any time prior to the time that any person becomes an acquiring person, redeem all, but not less than all, of the then outstanding rights at the redemption price.

    This summary description of the rights does not purport to be complete and is qualified in its entirety by reference to the rights agreement.


PLAN OF DISTRIBUTION

    Abbott may sell the securities:

14

    Abbott may distribute the securities from time to time in one or more transactions at a fixed price or prices, which may be changed, or at market prices prevailing at the time of sale, at prices related to the prevailing market prices or at negotiated prices.

    Abbott may designate agents to solicit offers to purchase the securities from time to time. These agents may be deemed to be underwriters, as defined in the Securities Act of 1933, involved in the offer or sale of the securities. The prospectus supplement will name the agents and any commissions Abbott pays them. Agents may be entitled to indemnification by Abbott against certain liabilities, including liabilities under the Securities Act of 1933, under agreements between Abbott and the agents, and the agents or their affiliates may extend credit to or engage in transactions with or perform services for Abbott in the ordinary course of business. Unless otherwise indicated in the prospectus supplement, any agent will be acting on a reasonable efforts basis for the period of its appointment.

    If Abbott uses any underwriters in the sale, Abbott will enter into an underwriting agreement with them at the time of sale. The names of the underwriters and the terms of the transaction will be set forth in the prospectus supplement that the underwriters use to make resales of the securities. The underwriters may be entitled under the relevant underwriting agreement to indemnification by Abbott against certain liabilities, including liabilities under the Securities Act of 1933, and the underwriters or their affiliates may extend credit to or engage in transactions with or perform services for Abbott in the ordinary course of business.

    If Abbott uses dealers in the sale of the securities, Abbott will sell the securities to those dealers, as principal. The dealers may then resell the securities to the public at varying prices to be determined by them at the time of resale. Dealers may be entitled to indemnification by Abbott against certain liabilities, including liabilities under the Securities Act of 1933, and the dealers or their affiliates may extend credit to or engage in transactions with or perform services for Abbott in the ordinary course of business.

    The debt securities are not proposed to be listed on a securities exchange, and any underwriters or dealers will not be obligated to make a market in debt securities. Abbott cannot predict the activity or liquidity of any trading in the debt securities.


LEGAL OPINIONS

    Certain legal matters in connection with the securities offered hereby will be passed upon for Abbott by Jose M. de Lasa, Esq., Abbott's Senior Vice President, General Counsel and Secretary, and by Mayer, Brown & Platt, Chicago, Illinois, and for the underwriters, dealers and agents, if any, by Skadden, Arps, Slate, Meagher & Flom (Illinois), Chicago, Illinois. As of June 15, 2001, Mr. de Lasa beneficially owned approximately 203,793 Abbott common shares and held options to acquire 539,885 shares, of which options to purchase 244,754 shares are currently exercisable. (These amounts include approximately 1,563 shares held for the benefit of Mr. de Lasa in the Abbott Laboratories Stock Retirement Trust pursuant to the Abbott Laboratories Stock Retirement Plan). The opinions of Mr. de Lasa, Mayer, Brown & Platt and Skadden, Arps, Slate, Meagher & Flom (Illinois) 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 the issuance and sale of any securities. The opinions of Mr. de Lasa, Mayer, Brown & Platt and Skadden, Arps, Slate, Meagher & Flom (Illinois) with respect to securities may be subject to other conditions and assumptions, as indicated in the prospectus supplement. Skadden, Arps, Slate, Meagher & Flom (Illinois) from time to time also represents Abbott in connection with certain other matters.

15


EXPERTS

    The Abbott Laboratories audited consolidated financial statements and schedule incorporated by reference in this prospectus have been audited by Arthur Andersen LLP, independent public accountants, as indicated in their reports with respect thereto, and are incorporated by reference herein in reliance upon the authority of said firm as experts in giving said reports.

    The BASF Pharmaceutical Business consolidated financial statements as of and for the years ended December 31, 2000 and 1999 incorporated by reference in this prospectus have been audited by Deloitte & Touche GmbH, independent public accountants, as set forth in their reports. In those reports, that firm states that with respect to certain subsidiaries its opinion is based on the reports of other independent public accountants, namely Ernst & Young Deutsche Allgemeine Treuhand AG and Asahi & Co. The financial statements referred to above have been incorporated by reference herein in reliance upon the authority of those firms as experts in giving said reports.


WHERE YOU CAN FIND MORE INFORMATION

    Abbott files annual, quarterly and special 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 450 Fifth Street, N.W., 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 documents 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 until Abbott has sold all of the securities to which this prospectus relates or the offering is otherwise terminated. Abbott's subsequent filings with the SEC will automatically update and supersede information in this prospectus.

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

    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.

16

    No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in this prospectus. You must not rely on any unauthorized information or representations. This prospectus is an offer to sell only the Notes offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus is current only as of its date.

TABLE OF CONTENTS
Prospectus Supplement

 
   Page
Abbott Laboratories   S-1
Forward-Looking Statements   S-7
Use of Proceeds   S-8
Capitalization   S-9
Ratio of Earnings to Fixed Charges   S-10
Description of Notes   S-11
Underwriting   S-15
Legal Opinions   S-16

Prospectus
About this Prospectus   2
Abbott Laboratories   2
Use of Proceeds   2
Description of Debt Securities   3
Description of Common Shares   12
Plan of Distribution   14
Legal Opinions   15
Experts   16
Where You Can Find More Information   16

$3,250,000,000

Abbott Laboratories

$1,650,000,000

5.125% Notes due July 1, 2004

$1,600,000,000

5.625% Notes due July 1, 2006

LOGO

Joint Book-Running Managers

Banc of America Securities LLC
Goldman, Sachs & Co.
Salomon Smith Barney

Banc One Capital Markets, Inc.
Morgan Stanley
ABN AMRO Incorporated
BMO Nesbitt Burns Corp.
First Union Securities, Inc.
ING Barings
SG Cowen
Wachovia Securities, Inc.
The Williams Capital Group, L.P.



QuickLinks

ABBOTT LABORATORIES
FORWARD-LOOKING STATEMENTS
USE OF PROCEEDS
CAPITALIZATION
RATIO OF EARNINGS TO FIXED CHARGES
DESCRIPTION OF NOTES
UNDERWRITING
LEGAL OPINIONS
ABOUT THIS PROSPECTUS
ABBOTT LABORATORIES
USE OF PROCEEDS
DESCRIPTION OF DEBT SECURITIES
DESCRIPTION OF COMMON SHARES
PLAN OF DISTRIBUTION
LEGAL OPINIONS
EXPERTS
WHERE YOU CAN FIND MORE INFORMATION