EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this Registration Statement of our report dated February 14, 1996 included in XOMA Corporation's Form 10-K for the year ended December 31, 1995, and to all refer- ences to our Firm included in this Registration Statement. ARTHUR ANDERSEN LLP San Francisco, California September 24, 1996