**Exhibit 23.1****Consent of Independent Registered Public Accounting Firm**We consent to the incorporation by reference in the following Registration Statements:(1) Registration Statement (Form S-3 No. 333-134565) of Onyx Pharmaceuticals, Inc., (2) Registration Statement (Form S-3 No. 333-122176) of Onyx Pharmaceuticals, Inc., (3) Registration Statement (Form S-3 No. 333-112436) of Onyx Pharmaceuticals, Inc., (4) Registration Statement (Form S-3 No. 333-111091) of Onyx Pharmaceuticals, Inc., (5) Registration Statement (Form S-3 No. 333-107217) of Onyx Pharmaceuticals, Inc., (6) Registration Statement (Form S-3 No. 333-106070) of Onyx Pharmaceuticals, Inc., (7) Registration Statement (Form S-3 No. 333-104025) of Onyx Pharmaceuticals, Inc., (8) Registration Statement (Form S-3 No. 333-89850) of Onyx Pharmaceuticals, Inc., (9) Registration Statement (Form S-3 No. 333-46366) of Onyx Pharmaceuticals, Inc., (10) Registration Statement (Form S-3 No. 333-37144) of Onyx Pharmaceuticals, Inc., (11) Registration Statement (Form S-3 No. 333-33322) of Onyx Pharmaceuticals, Inc., (12) Registration Statement (Form S-3 No. 333-49285) of Onyx Pharmaceuticals, Inc., (13) Registration Statement (Form S-8 No. 333-134567) pertaining to the 1996 Employee StockPurchase Plan of Onyx Pharmaceuticals, Inc., (14) Registration Statement (Form S-8 No. 333-126089) pertaining to the 2005 Equity IncentivePlan, 1996 Equity Incentive Plan, and the 1996 Non-Employee Directors’ Stock Option Plan ofOnyx Pharmaceuticals, Inc., (15) Registration Statement (Form S-8 No. 333-120324) pertaining to the 1996 Equity Incentive Planof Onyx Pharmaceuticals, Inc., (16) Registration Statement (Form S-8 No. 333-110469) pertaining to the 1996 Equity Incentive Planand the 1996 Non-Employee Directors’ Plan of Onyx Pharmaceuticals, Inc., (17) Registration Statement (Form S-8 No. 333-96895) pertaining to the 1996 Equity Incentive Planand the 1996 Employee Stock Purchase Plan of Onyx Pharmaceuticals, Inc., (18) Registration Statement (Form S-8 No. 333-64706) pertaining to the 1996 Equity Incentive Planand the 1996 Non-Employee Directors’ Stock Option Plan of Onyx Pharmaceuticals, Inc., (19) Registration Statement (Form S-8 No. 333-48146) pertaining to the 1996 Equity Incentive Plan,the 1996 Non-Employee Directors’ Stock Option Plan and the Employee Stock Purchase Plan ofOnyx Pharmaceuticals, Inc., (20) Registration Statement (Form S-8 No. 333-84113) pertaining to the 1996 Equity Incentive Planof Onyx Pharmaceuticals, Inc., (21) Registration Statement (Form S-8 No. 333-60805) pertaining to the 1996 Equity Incentive Planand the 1996 Employee Stock Purchase Plan of Onyx Pharmaceuticals, Inc., (22) Registration Statement (Form S-8 No. 333-34681) pertaining to the 1996 Equity Incentive Plan,as amended, of Onyx Pharmaceuticals, Inc., (23) Registration Statement (Form S-8 No. 333-04839) pertaining to the 1996 Equity Incentive Plan,the 1996 Employee Stock Purchase Plan, and the 1996 Non-Employee Directors’ Stock Option Planof Onyx Pharmaceuticals, Inc.;of our reports dated February 28, 2007, with respect to the financial statements of OnyxPharmaceuticals, Inc., Onyx Pharmaceuticals, Inc. management’s assessment of the effectiveness ofinternal control over financial reporting, and the effectiveness of internal control over financialreporting of Onyx Pharmaceuticals, Inc., included in this Annual Report (Form 10-K) of OnyxPharmaceuticals, Inc. for the year ended December 31, 2006./s/ Ernst& Young LLP      Palo Alto, California