EXHIBIT 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of Apex Silver Mines Limited (the “Company”) on Form 10-K for the year ended December 31, 2006, as filed with the SEC on the date hereof (the “Report”), the undersigned hereby certifies, pursuant to 18 U.S.C. §1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

(1)The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

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

/s/ Jeffrey G. Clevenger

Jeffrey G. Clevenger

President and Chief Executive Officer

April 2, 2007

/s/ Gerald J. Malys

Gerald J. Malys

Senior Vice President and Chief Financial Officer

April 2, 2007