Exhibit 99.1

                            CERTIFICATION PURSUANT TO
                              18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of ZymoGenetics, Inc. (the Company) on Form
10-K for the period ended December 31, 2002 as filed with the Securities and
Exchange Commission on the date hereof (the Report), I, Bruce L.A. Carter, Chief
Executive Officer of the Company, certify, pursuant to 18 U.S.C. (S)1350, as
adopted pursuant to (S)906 of the Sarbanes-Oxley Act of 2002, that:

          (1) The Report fully complies with the requirements of section 13(a)
or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m or 780 (d)); and

          (2) The information contained in the Report fairly presents, in all
material respects, the financial condition and results of operations of the
Company.



/s/  Bruce L.A. Carter
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Bruce L.A. Carter
Chief Executive Officer
March 25, 2003

A signed original of this writen statement, required by Section 906, has been
provided to the Company and will be retained by the Company and furnished to the
Securities and Exchange Commission or its staff upon request.