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

Each of the undersigned hereby certifies, in his capacity as an officer of The Corporate Executive Board Company (the “Company”), for purposes of 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to the best of his knowledge:

• The Quarterly Report on Form 10-Q of the Company for the quarterly period ended June 30, 2005 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

• The information contained in such Quarterly Report on Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Thomas L. Monahan III
Thomas L. Monahan III
Chief Executive Officer
August 9, 2005

/s/ Timothy R. Yost
Timothy R. Yost
Chief Financial Officer
August 9, 2005