EXHIBIT 32.1



                            CERTIFICATION PURSUANT TO
                               18 U.S.C. ss.1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

         In connection with the Quarterly  Report of Natural Gas Services Group,
Inc. (the "Company") on Form 10-QSB for the period ended March 31, 2005 as filed
with the Securities and Exchange  Commission on the date hereof (the  "Report"),
I, Stephen C. Taylor, Chief Executive Officer of the Company,  certify, pursuant
to 18 U.S.C.  ss.1350,  as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that:

1.       The Report fully  complies  with the  requirements  of Section 13(a) or
         15(d) of the Securities Exchange Act of 1934; and

2.       The  information  contained  in  the  Report  fairly  presents,  in all
         material respects, the financial condition and results of operations of
         the Company.


                                     /s/Stephen Taylor
                                    -----------------------
                                    Stephen Taylor
                                    Chief Executive Officer

                                    May 16, 2005