<PAGE>
EXHIBIT 23.1
CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS
We consent to the reference to our firm under the caption "Experts" in Amendment
No. 1 to the Registration Statement (Form S-3) and related Prospectus of Onyx
Pharmaceuticals, Inc. for the registration of 3,450,000 shares of its common
stock and to the incorporation by reference therein of our report dated
February 18, 2000, with respect to the financial statements of Onyx
Pharmaceuticals, Inc. included in its Annual Report (Form 10-K) for the year
ended December 31, 1999, filed with the Securities and Exchange Commission.
/S/ ERNST & YOUNG LLP
Palo Alto, California
October 9, 2000
