EXHIBIT 23.1 CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-04839) pertaining to the 1996 Employee Stock Purchase Plan, the 1996 Non-Employee Directors' Stock Option Plan and the 1996 Equity Incentive Plan of Onyx Pharmaceuticals, Inc. of our report dated February 28, 1997, except as to Note 10 as to which the date is March 21, 1997, with respect to the financial statements of Onyx Pharmaceuticals, Inc. included in this Annual Report (Form 10-K) for the year ended December 31, 1996. ERNST & YOUNG LLP Palo Alto, California March 28, 1997