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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 10-Q/A

(Mark one)

[X]     Quarterly report pursuant to Section 13 or 15(d) of the Securities
        Exchange Act of 1934. For the quarterly period ended March 31, 1998.

[ ]     Transition report pursuant to Section 13 or 15(d) of the Securities
        Exchange Act of 1934. For the transition period from _______________ to 
        _______________.

                             Commission File Number
                                     0-19290


                             COR THERAPEUTICS, INC.
             (Exact name of registrant as specified in its charter)

           Delaware                                               94-3060271
(State or other jurisdiction of                               (I.R.S. employer
incorporation or organization)                               identification no.)


          256 East Grand Avenue, South San Francisco, California 94080
              (Address of principal executive offices and zip code)

                                 (650) 244-6800
              (Registrant's telephone number, including area code)

        Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

                              Yes [X]   No [ ]

        Indicate the number of shares outstanding of each of the issuer's
classes of common stock, as of the latest practicable date.

        Common Stock $.0001 par value                       24,088,791
                                                            ----------
                                                  Outstanding at April 30, 1998


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                             COR THERAPEUTICS, INC.


PART II. OTHER INFORMATION

Item 1. Legal proceedings. Note 2 of the Notes to Financial Statements is
        incorporated by reference in Part II hereof.

Item 6. Exhibits and Reports on Form 8-K

        (a)     Exhibits 
                  27.1 Financial Data Schedule.(1)

        (b)     Reports
                  There were no reports on Form 8-K filed for the quarter ended
                  March 31, 1998.


                                   SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


Date: July 23, 1998

COR THERAPEUTICS, INC.


By: /s/ VAUGHN M. KAILIAN                   By: /s/ LAURA A. BREGE
    ----------------------------                -----------------------------
    Vaughn M. Kailian                           Laura A. Brege
    President and Chief Executive Officer       Senior Vice President, Finance
                                                  and Chief Financial Officer

                                            By: /s/ PETER S. RODDY
                                                ------------------------------
                                                Peter S. Roddy
                                                Director, Finance and Controller



(1) This 10-Q/A corrects an error by the Filing Agent in the transmission of
    Exhibit 27.1, Financial Data Schedule. There are no other changes to the
    Report on form 10-Q as previously filed.


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