EXHIBIT 23.1: CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in the following Registration Statements of Paychex, Inc. of our reports dated July 13, 2006 with respect to the consolidated financial statements of Paychex, Inc., Paychex, Inc.'s management's assessment of the effectiveness of internal control over financial reporting, and the effectiveness of internal control over financial reporting of Paychex, Inc., included in this Annual Report (Form 10-K) for the year ended May 31, 2006. Form Registration Statement No. Description - ---- -------------------------- ----------- S-8 No. 33-64389 1995 Stock Incentive Plan S-8 No. 333-65191 1998 Stock Incentive Plan S-8 No. 333-84055 401(k) Incentive Retirement Plan S-8 No. 333-101074 2002 Stock Incentive Plan S-8 No. 333-129571 Non-Qualified Stock Option Agreement S-8 No. 333-129572 2002 Stock Incentive Plan, as amended and restated /s/ Ernst & Young LLP Cleveland, Ohio July 17, 2006