Exhibit 24

FAIR ISAAC CORPORATION

Power of Attorney
of Director and/or Officer

      KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned director and/or officer of FAIR ISAAC CORPORATION, a Delaware corporation (“Company”), does hereby make, constitute and appoint CHARLES M. OSBORNE and ANDREA M. FIKE, and each or any one of them, the undersigned’s attorney-in-fact, with full power of substitution, for the undersigned in any and all capacities to sign and affix the undersigned’s name as such director and/or officer of said Company to a Registration Statement or Registration Statements, on Form S-8 or other applicable form, and all amendments, including post-effective amendments, thereto regarding the Company’s 1992 Long-Term Incentive Plan (As Amended and Restated Effective August 26, 2003), and The Fair Isaac Supplemental Retirement and Savings Plan (As Amended and Restated Effective December 1, 2004), to be filed by said Company with the Securities and Exchange Commission, Washington, D.C., in connection with the registration under the Securities Act of 1933, as amended, of shares of stock and deferred compensation obligations of said Company and to file the same, with all exhibits thereto and other supporting documents, with said Commission, granting unto the attorney-in-fact, full power and authority to do and perform any and all acts necessary or incidental to the performance and execution of the powers herein expressly granted.

      IN WITNESS WHEREOF, the undersigned has hereunto set the undersigned’s hand this 19th day of January, 2005.

/s/ Thomas G. Grudnowski	/s/ Tony J. Christianson
Thomas G. Grudnowski	Tony J. Christianson
/s/ Charles M. Osborne	/s/ Alex W. Hart
Charles M. Osborne	Alex W. Hart
/s/ Michael J. Pung	/s/ Philip G. Heasley
Michael J. Pung	Philip G. Heasley
/s/ A. George Battle	/s/ Guy R. Henshaw
A. George Battle	Guy R. Henshaw
/s/ Andrew Cecere	/s/ David S.P. Hopkins
Andrew Cecere	David S.P. Hopkins
/s/ Margaret L. Taylor
Margaret L. Taylor