SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 20)* Abbott Laboratories ----------------------------------------------------------- (Name of Issuer) Common shares without par value ----------------------------------------------------------- (Title of Class of Securities) 002824 10 0 (CUSIP Number) *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). (Continued on following page(s)) Page 1 of 11 Pages

CUSIP No. 002824 10 0 13G Page 2 of 11 Pages - ------------------------------------------------------------------------------ 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON - ------------------------------------------------------------------------------ Abbott Laboratories Stock Retirement Trust I.R.S. Identification No. 36-6047554 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) / / (b) /X/ - ------------------------------------------------------------------------------ 3 SEC USE ONLY - ------------------------------------------------------------------------------ 4 CITIZENSHIP OR PLACE OF ORGANIZATION Illinois - ------------------------------------------------------------------------------ 5 SOLE VOTING POWER NUMBER OF 0 --------------------------------------------------------- SHARES 6 SHARED VOTING POWER BENEFICIALLY OWNED BY 107,072,842 --------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 0 --------------------------------------------------------- WITH 8 SHARED DISPOSITIVE POWER 107,072,842 --------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 107,072,842 - ------------------------------------------------------------------------------ 10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - ------------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7.1% - ------------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON* EP - ------------------------------------------------------------------------------ *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 002824 10 0 13G Page 3 of 11 Pages - ------------------------------------------------------------------------------ 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Gary P. Coughlan ###-##-#### - ------------------------------------------------------------------------------ 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) / / (b) /X/ - ------------------------------------------------------------------------------ SEC USE ONLY 3 - ------------------------------------------------------------------------------ 4 CITIZENSHIP OR PLACE OF ORGANIZATION United States - ------------------------------------------------------------------------------ 5 SOLE VOTING POWER 263,457 shares - (Does not include shares held NUMBER OF direct in the Abbott Laboratories Stock Retirement Trust for the benefit of the reporting person.) ---------------------------------------------------------- SHARES 6 SHARED VOTING POWER BENEFICIALLY OWNED BY 110,068,668 - See Attached Exhibit 1 ---------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING 263,457 shares (see note in 5 above) PERSON direct ---------------------------------------------------------- WITH 8 SHARED DISPOSITIVE POWER 110,068,668 - as Co-Trustee, Abbott Laboratories Stock Retirement Trust. ---------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 110,591,175 - (Total of 5 + 6 + 259,050 shares - right to acquire by exercise of stock options.) - ------------------------------------------------------------------------------ 10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - ------------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7.3% - ------------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON* IN - ------------------------------------------------------------------------------ *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 002824 10 0 13G Page 4 of 11 Pages - ------------------------------------------------------------------------------ 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Thomas C. Freyman ###-##-#### - ------------------------------------------------------------------------------ 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) / / (b) /X/ - ------------------------------------------------------------------------------ 3 SEC USE ONLY - ------------------------------------------------------------------------------ 4 CITIZENSHIP OR PLACE OF ORGANIZATION United States - ------------------------------------------------------------------------------ 5 SOLE VOTING POWER 56,242 shares - (Does not include shares held in NUMBER OF direct the Abbott Laboratories Stock Retirement Trust for the benefit of the reporting person.) ---------------------------------------------------------- SHARES 6 SHARED VOTING POWER BENEFICIALLY OWNED BY 110,068,668 - See Attached Exhibit 1 ---------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING 56,242 shares (see note in 5 above) PERSON direct ---------------------------------------------------------- WITH 8 SHARED DISPOSITIVE POWER 110,068,668 - as Co-Trustee, Abbott Laboratories Stock Retirement Trust. - ------------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 110,258,812 - (Total of 5 + 6 + 133,902 shares - right to acquire by exercise of stock options.) - ------------------------------------------------------------------------------ 10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - ------------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7.3% - ------------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON* IN - ------------------------------------------------------------------------------ *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 002824 10 0 13G Page 5 of 11 Pages - ------------------------------------------------------------------------------ 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Ellen M. Walvoord ###-##-#### - ------------------------------------------------------------------------------ 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) / / (b) /X/ - ------------------------------------------------------------------------------ 3 SEC USE ONLY - ------------------------------------------------------------------------------ 4 CITIZENSHIP OR PLACE OF ORGANIZATION United States - ------------------------------------------------------------------------------ 5 SOLE VOTING POWER 168,900 shares - (Does not include shares held in NUMBER OF direct the Abbot Laboratories Stock Retirement Trust for the benefit of the reporting person.) --------------------------------------------------------- SHARES 6 SHARED VOTING POWER BENEFICIALLY OWNED BY 110,068,668 - See Attached Exhibit 1 --------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING 168,900 shares (see note in 5 above) PERSON direct --------------------------------------------------------- WITH 8 SHARED DISPOSITIVE POWER 110,068,668 - as Co-Trustee, Abbott Laboratories Stock Retirement Trust. - ------------------------------------------------------------------------------ 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 110,376,175 - (Total of 5 + 6 + 138,607 shares - right to acquire by exercise of stock options.) - ------------------------------------------------------------------------------ 10 CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - ------------------------------------------------------------------------------ 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7.3% - ------------------------------------------------------------------------------ 12 TYPE OF REPORTING PERSON* IN - ------------------------------------------------------------------------------ *SEE INSTRUCTION BEFORE FILLING OUT!

Item 1(a) Name of Issuer: Abbott Laboratories Item 1(b) Address of Issuer's Principal Executive Offices: 100 Abbott Park Road Abbott Park, Illinois 60064-3500 Item 2(a) Name of Persons Filing: Abbott Laboratories Stock Retirement Trust Gary P. Coughlan Thomas C. Freyman Ellen M. Walvoord Item 2(b) Address of Principal Business Office: 100 Abbott Park Road Abbott Park, Illinois 60064-3500 Item 2(c) Citizenship: Abbott Laboratories Stock Retirement Trust - Illinois. Gary P. Coughlan, Thomas C. Freyman, and Ellen M. Walvoord - United States Item 2(d) Title of Class of Securities: Common shares without par value Item 2(e) CUSIP Number: 002824 10 0 Item 3. If this statement is filed pursuant to Section 240.13d-1(b) or 240.13d-2(b), check whether the person filing is an: [X] Employee Benefit Plan or endowment fund in accordance with Section 240.13d-1(b)(ii)(F). Page 6 of 11 pages

Item 4. Ownership (a) (See cover pages 2, 3, (b) 4 and 5, Items 5 through (c) 9 and 11.) Item 5. Ownership of Five Percent or Less of a Class Not applicable. Item 6. Ownership of More than Five Percent on Behalf of Another Person. The shares owned by the Abbott Laboratories Stock Retirement Trust and the dividends thereon are held for the benefit of participants of the Abbott Laboratories Stock Retirement Plan pursuant to terms of that Plan and the Trust. The Abbott Laboratories Stock Retirement Plan is a qualified profit sharing plan. As of December 31, 1998, there were 36,364 participants with share balances in the Plan. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company. Not applicable. Item 8. Identification and Classification of Members of the Group. Not applicable. Item 9. Notice of Dissolution of Group. Not applicable. Item 10. Certification. Not applicable. Signature After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. This statement is filed on behalf of each individual listed below pursuant to their agreement. Date: February 10, 1999 /s/ Gary P. Coughlan ABBOTT LABORATORIES STOCK - --------------------- RETIREMENT TRUST Gary P. Coughlan /s/ Thomas C. Freyman - --------------------- Thomas C. Freyman /s/ Ellen M. Walvoord /s/ Thomas C. Freyman - --------------------- ------------------------------ Ellen M. Walvoord Thomas C. Freyman, Chairman of Trustees, Abbott Laboratories Stock Retirement Trust Page 7 of 11 pages

EXHIBIT 1 Schedule 13G Amendment No. 20 Abbott Laboratories Common shares without par value CUSIP Number 002824 10 0 Messrs. Coughlan and Freyman and Ms. Walvoord are Co-trustees of the Abbott Laboratories Stock Retirement Trust, committee members of a committee established under the Abbott Laboratories Stock Retirement Trust (Puerto Rico), Trustees of the Abbott Laboratories Employee Benefit Trust, and members of the Abbott Stock Committee for the Abbott Laboratories Ashland Union 401(k) Trust. As such, each of them has shared voting power over the 110,068,668 shares held by those trusts. This total is comprised of the following components: Number of Shares Name of Trust ---------------- ------------- 107,072,842 Abbott Laboratories Stock Retirement Trust 2,918,829 Abbott Laboratories Stock Retirement Trust (Puerto Rico) 52,000 Abbott Laboratories Employee Benefit Trust 24,997 Abbott Laboratories Ashland Union 401(k) Trust Page 8 of 11 Pages

Disclaimer of Beneficial Ownership under Rule 13d-4 ---------------------------------- The filing of Schedule 13G Amendment 20 on behalf of the Abbott Laboratories Stock Retirement Trust does not constitute an admission that the undersigned is, for purposes of Section 13(d) of the Securities and Exchange Act of 1934, the beneficial owner of any securities covered by the Schedule. Pursuant to Rule 13d-4 of the Act, the undersigned disclaims such ownership with respect to any shares listed therein of which he would not otherwise be deemed to be beneficial owner. /s/ Gary P. Coughlan ------------------------------ Gary P. Coughlan Date: February 10, 1999 Page 9 of 11 Pages

Disclaimer of Beneficial Ownership under Rule 13d-4 ---------------------------------- The filing of Schedule 13G Amendment 20 on behalf of the Abbott Laboratories Stock Retirement Trust does not constitute an admission that the undersigned is, for purposes of Section 13(d) of the Securities and Exchange Act of 1934, the beneficial owner of any securities covered by the Schedule. Pursuant to Rule 13d-4 of the Act, the undersigned disclaims such ownership with respect to any shares listed therein of which he would not otherwise be deemed to be beneficial owner. /s/ Thomas C. Freyman ------------------------------ Thomas C. Freyman Date: February 10, 1999 Page 10 of 11 Pages

Disclaimer of Beneficial Ownership under Rule 13d-4 ---------------------------------- The filing of Schedule 13G Amendment 20 on behalf of the Abbott Laboratories Stock Retirement Trust does not constitute an admission that the undersigned is, for purposes of Section 13(d) of the Securities and Exchange Act of 1934, the beneficial owner of any securities covered by the Schedule. Pursuant to Rule 13d-4 of the Act, the undersigned disclaims such ownership with respect to any shares listed therein of which she would not otherwise be deemed to be beneficial owner. /s/ Ellen M. Walvoord ---------------------------- Ellen M. Walvoord Date: February 10, 1999 Page 11 of 11 Pages