Exhibit 32.1

CERTIFICATION
 
Pursuant to the requirement set forth in Rule 13a-14(b) of the Securities Exchange Act of 1934, as amended, (the “Exchange Act”) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. §1350), John Varian, Chief Executive Officer of XOMA Corporation (the “Company”), and Fred Kurland, Chief Financial Officer of the Company, each hereby certifies that, to the best of his or her knowledge:

1.       The Company’s Amendment No. 1 to the Quarterly Report on Form 10-Q for the period ended March 31, 2014, to which this Certification is attached as Exhibit 32.1 (the “Periodic Report”), fully complies with the requirements of Section 13(a) or Section 15(d) of the Exchange Act; and

2.       The information contained in the Periodic Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

IN WITNESS WHEREOF, the undersigned have set their hands hereto as of the 7th day of August, 2014.

 
/s/    JOHN VARIAN
 
John Varian
Chief Executive Officer
 
 
 
/s/    FRED KURLAND
 
Fred Kurland
Vice President, Finance, Chief Financial Officer and Secretary

This certification accompanies the Form 10-Q to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of XOMA Corporation under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made before or after the date of the Form 10-Q), irrespective of any general incorporation language contained in such filing.