Exhibit 5-1




                                 Clinton Square
                                 P.O. Box 31051
                         Rochester, New York 14603-1051
                                 (585) 263-1000
                               Fax: (585) 263-1600

                                November 7, 2002



Paychex, Inc.
911 Panorama Trail South
Rochester, New York  14625

Ladies and Gentlemen:

We have acted as counsel to Paychex, Inc., a Delaware corporation (the
"Company"), in connection with the Registration Statement on Form S-8 (the
"Registration Statement") to be filed by the Company on November 7, 2002 with
the Securities and Exchange Commission (the "Commission") under the Securities
Act of 1933, as amended (the "Act"), for the purpose of registering with the
Commission the issuance and sale of 9,107,569 shares of Common Stock of the
Company, par value $.01 per share (the "Common Stock"), pursuant to the
Company's 2002 Stock Incentive Plan (the "Plan").

This opinion is being delivered to you in connection with the Registration
Statement.

We have examined originals or copies, certified or otherwise identified to our
satisfaction, of all such records of the Company and all such agreements,
certificates of public officials, certificates of officers or other
representatives of the Company, and such other documents, certificates and
corporate or other records as we have deemed necessary or appropriate as a basis
for the opinions set forth herein, including (i) the Amended Certificate of
Incorporation of the Company, (ii) the By-Laws of the Company, as amended to the
date hereof, and (iii) the Plan. As to questions of fact material to our
opinions expressed herein, we have, when relevant facts were not independently
established, relied upon certificates of, and information received from, the
Company and/or representatives of the Company. We have made no independent
investigation of the facts stated in such certificates or as to any information
received from the Company and/or representatives of the Company and do not opine
as to the accuracy of such factual matters. We also have relied, without
investigation, upon certificates and other documents from, and conversations
with, public officials.

Members of our firm involved in the preparation of this opinion are licensed to
practice law in the State of New York and we do not purport to be experts on, or
to express any opinion herein



concerning, the laws of any jurisdiction other than the laws of the State of New
York and the General Corporation Law of the State of Delaware.

Based upon and subject to the foregoing, and the other qualifications and
limitations contained herein, and after (a) the above-referenced Registration
Statement has become effective under the Act and assuming that such
effectiveness remains in effect throughout the period during which shares of
Common Stock are offered and sold pursuant to the Plan, (b) the shares of Common
Stock to be offered and sold pursuant to the Plan have, if required, been duly
qualified or registered, as the case may be, for sale under applicable
securities laws and all applicable securities laws are complied with, (c) all
necessary action by the Board of Directors of the Company shall have been taken
to duly authorize the offer, issuance and sale of Common Stock to be offered and
sold pursuant to the Plan, and (d) the shares of Common Stock to be offered and
sold pursuant to the Plan have been delivered pursuant to and in accordance with
the terms of the Plan and related agreements and instruments, we are of the
opinion that the 9,107,569 shares of Common Stock to be offered and sold
pursuant to the Plan will have been duly authorized, validly issued, fully paid
and non-assessable.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In giving this consent, we do not thereby admit that we
are in the category of persons whose consent is required under Section 7 of the
Act or the rules and regulations of the Commission thereunder.

This opinion is intended solely for your benefit in connection with the
transactions described above and, except as provided in the immediately
preceding paragraph, may not be otherwise communicated to, reproduced, filed
publicly or relied upon by, any other person or entity for any other purpose
without our express prior written consent. This opinion is limited to the
matters stated herein, and no opinion or belief is implied or may be inferred
beyond the matters expressly stated herein. The opinions expressed herein are
rendered as of the date hereof, and we disclaim any undertaking to advise you of
changes in law or fact which may affect the continued correctness of any of our
opinions as of a later date.

                                          Very truly yours,


                                          /s/ Nixon Peabody LLP