NATURAL GAS SERVICES GROUP, INC.

                                                                    EXHIBIT 99.1


                            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,  2003,  as
filed with the  Securities  and  Exchange  Commission  on the date  hereof  (the
"Report"), I, Wayne L. Vinson, 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/Wayne L. Vinson
                                                     -----------------------
                                                     Wayne L. Vinson
                                                     Chief Executive Officer

                                                     May 16, 2003