Amgen (AMGN) S-4/A Registration of securities issued in business combination transactions (amended)

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

          We consent to the reference to our firm under the caption “Experts” in Amendment No. 1 to the Registration Statement (Form S-4 No. 333-123300) and related Prospectus of Amgen Inc. for the registration of 4% Senior Notes due 2009 and 4.85% Senior Notes due 2014 and to the incorporation by reference therein of our reports dated March 4, 2005, with respect to the consolidated financial statements and schedule of Amgen Inc., Amgen Inc. management’s assessment of the effectiveness of internal control over financial reporting, and the effectiveness of internal control over financial reporting of Amgen Inc., included in its Annual Report (Form 10-K) for the year ended December 31, 2004, filed with the Securities and Exchange Commission.

/s/ ERNST & YOUNG LLP

Los Angeles, CA
April 5, 2005