FORM 8-A


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


               FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                   PURSUANT TO SECTION 12(b) OR 12(g) OF THE
                         SECURITIES EXCHANGE ACT OF 1934



                            COMFORT SYSTEMS USA, INC.
             (exact name of registrant as specified in its charter)



            Delaware                                76-0526487
     (State of incorporation           (I.R.S. Employer Identification No.)
        or organization)



    4801 Woodway, Suite 300E
         Houston, Texas                                77056
(Address of principal executive offices)            (Zip Code)



           Securities to be registered to Section 12(b) of the Act:


       Title of each class                Name of each exchange on which
       to be so registered                each class is to be registered


          Common Stock,                       New York Stock Exchange
    par value $.01 per share


       Securities to be registered pursuant to Section 12(g) of the Act:

                                      None


Item 1.   Description of Registrant's Securities to be Registered.

      The information set forth under the caption "Description of Capital Stock
- -- Common Stock and Restricted Common Stock" set forth in the Registration
Statement on Form S-1 (Registration No. 333-24021) of Comfort Systems USA, Inc.
filed with the Securities and Exchange Commission is incorporated herein by
reference.

Item 2.   Exhibits.

1.    All exhibits required by Instruction II to Item 2 will be supplied to The
      New York Stock Exchange.


                                    SIGNATURE

      Pursuant to the requirements of Section 12 of the Securities Exchange Act
of 1934, the registrant has duly caused this registration statement to be signed
on its behalf by the undersigned, thereto duly authorized.

                                          COMFORT SYSTEMS USA, INC.

                                          By:   /S/ FRED M. FERREIRA

                                                Fred M. Ferreira
                                                Chairman of the Board,
                                                Chief Executive Officer and
                                                President

Date: May 9, 1997