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

I, Paul A. Ricci, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Nuance Communications, Inc. on Form 10-K for the period ended September 30, 2010 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 Annual Report on Form 10-K fairly presents in all material respects the financial condition and results of operations of Nuance Communications, Inc.

By:  /s/  Paul A. Ricci

Paul A. Ricci

Chief Executive Officer and Chairman of the Board

November 29, 2010

I, Thomas L. Beaudoin, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Nuance Communications, Inc. on Form 10-K for the period ended September 30, 2010 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 Annual Report on Form 10-K fairly presents in all material respects the financial condition and results of operations of Nuance Communications, Inc.

By:  /s/  Thomas L. Beaudoin

Thomas L. Beaudoin

Executive Vice President and Chief Financial Officer

November 29, 2010