EXHIBIT 23.1

               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS


         We consent to the reference to our firm under the caption "Experts" in
the Registration Statement (Form S-3) and related Prospectus of XOMA Ltd. for
the registration of 6,395,000 common shares and to the incorporation by
reference therein of our report dated February 18, 2000 with respect to the 1999
and 1998 consolidated financial statements of XOMA Ltd. 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
April 27, 2000