Exhibit 32.1

URANIUM RESOURCES, INC.

650 S. Edmonds Lane, Suite 108, Lewisville, TX 75067

972.219.3330 Phone 972.219.3311 Fax

November 13, 2003

Securities and Exchange Commission

450 5^th Street, N.W.

Washington, D.C. 20549

CERTIFICATION OF CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Paul K. Willmott, President and Chief Executive Officer of Uranium Resources, Inc. (the “Company”), certify, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(1) The Quarterly Report on Form 10-Q of the Company for the period ended September 30, 2003 which this certification accompanies 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/    PAUL K. WILLMOTT

Paul K. Willmott

President and Chief Executive Officer

November 13, 2003