Autodesk (ADSK) 10-Q 2005 Q3 Quarterly report

Exhibit 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER

PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Based on my knowledge, I, Carol A. Bartz, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of Autodesk, Inc. on Form 10-Q for the quarterly period ended October 31, 2004 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Form 10-Q fairly presents in all material respects the financial condition and results of operations of Autodesk, Inc.

December 9, 2004

/s/    CAROL A. BARTZ        

Carol A. Bartz

Chairman, Chief Executive Officer and President

Based on my knowledge, I, Alfred J. Castino, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of Autodesk, Inc. on Form 10-Q for the quarterly period ended October 31, 2004 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Form 10-Q fairly presents in all material respects the financial condition and results of operations of Autodesk, Inc.

December 9, 2004

/s/    ALFRED J. CASTINO        

Alfred J. Castino

Senior Vice President and Chief Financial Officer