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                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  FORM 10-QSB/A

                (X) QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
                For the quarterly period ended September 30, 2002

                                       OR

                 ( ) TRANSITION REPORT UNDER SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                   For the transition period from_____ to_____

Commission File Number 1-31398

                        NATURAL GAS SERVICES GROUP, INC.
        (Exact name of small business issuer as specified in its charter)

               Colorado                                        75-2811855
     (State or other jurisdiction of                       (I.R.S. Employer
      incorporation or organization)                       Identification No.)

                                  2911 SCR 1260
                              Midland, Texas 79706
                    (Address of principal executive offices)

                                 (915) 563-3974
                           (Issuer's Telephone number)

                                       N/A
     ----------------------------------------------------------------------
              (Former name, former address and former fiscal year,
                         if changed since last report)

                APPLICABLE ONLY TO ISSUERS INVOLVED IN BANKRUPTCY
                   PROCEEDINGS DURING THE PRECEDING FIVE YEARS

Check whether the  registrant  filed all  documents  and reports  required to be
filed by Section 12, 13 or 15(d) of the Exchange Act after the  distribution  of
securities under a plan confirmed by a court.

                                  Yes    No
                                     ---   ----

                      APPLICABLE ONLY TO CORPORATE ISSUERS

State the number of shares outstanding of each of the issuer's classes of common
equity, as of the latest practicable date.

                                                           Outstanding at
            Class                                         October 31, 2002
- -----------------------------                      -----------------------------

Common Stock, $.001 par value                                4,857,632
                                                   -----------------------------

Transitional Small Business Disclosure Format (Check one):  Yes    No X
                                                               ---   ---
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                        NATURAL GAS SERVICES GROUP, INC.


Commission File Number:  1-31398

Quarter Ended September 30, 2002


FORM 10-QSB/A


Part II - OTHER INFORMATION...............................................Page 3

Item 2.  Changes in Securities............................................Page 3

Item 6.  Exhibits and Reports on Form 8-K.................................Page 4

Signatures................................................................Page 4


























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                        NATURAL GAS SERVICES GROUP, INC.


Commission File Number:  1-31398
Quarter Ended September 30, 2002
Form 10-QSB/A

PART II - OTHER INFORMATION


Item 2.  Changes in Securities

(d) On October 21, 2002, our  Registration  Statement  (File No.  333-88314) was
declared  effective.  The offering closed on October 24, 2002, after the sale of
1,500,000  shares of our common stock and warrants to purchase  1,500,000 shares
of our common stock. The representative of the underwriters for our offering was
Neidiger,Tucker,Bruner, Inc.

Not including shares of common stock and warrants  underlying the  underwriters'
over-allotment option and shares of common stock and warrants underlying options
that were to be issued to the representative of the underwriters,  we registered
1,650,000  shares of our common  stock for sale at a maximum  offering  price of
$5.75 per share for an aggregate  amount of $9,487,500  and warrants to purchase
1,650,000  shares of our common  stock for sale at a maximum  offering  price of
$0.25 per  warrant  for an  aggregate  amount of  $412,500.  We also  registered
1,650,000 shares of our common stock for sale upon exercise of the warrants at a
maximum offering price of $7.1875 per share for an aggregate of $11,859,375.

We also  registered  247,500  shares of our  common  stock for sale at a maximum
offering  price of $5.75 per share for an  aggregate  amount of  $1,423,125  and
warrants to purchase  247,500  shares of our common  stock for sale at a maximum
offering price of $0.25 per warrant for an aggregate amount of $61,875 that were
issuable  upon  exercise of the  underwriter's  over-allotment  option.  We also
registered  247,500  shares of our common  stock for sale upon  exercise  of the
warrants  included  in the  underwriter's  over-allotment  option  for sale at a
maximum offering price of $7.1875 per share for an aggregate of $1,778,906.

In addition,  as part of the offering,  we also registered 165,000 shares of our
common  stock,  warrants  to  purchase  165,000  shares of our common  stock and
165,000  shares of our common stock  underlying  the options to be issued to the
representative of the underwriters.

Subsequent to the effective time of the Registration Statement, we and Neidiger,
Tucker,  Bruner,  Inc. agreed to reduce the primary offering to 1,500,000 shares
of common  stock which were sold at $5.00 per share for an  aggregate  amount of
$7,500,000 and warrants to purchase  1,500,000  shares of our common stock which
warrants were sold for $0.25 per warrant for an aggregate amount of $375,000.

When we and Neidiger, Tucker, Bruner, Inc. agreed to reduce the primary
offering, the number of shares of our common stock and the number of warrants
(including the underlying shares of common stock) underlying the underwriter's
over-allotment option was reduced to 225,000 and the prices of each were reduced
to the prices set forth above. To date, the underwriters have not exercised
their over-allotment option.

As a result of the reduction in the primary offering,  the representative of the
underwriters received options to purchase 150,000 shares of our common stock and
warrants to purchase  150,000  shares of our common stock at prices of $6.25 and
$0.3125,   respectively.   The   representative's   warrants   included  in  the
representative's options are exercisable at $7.8125 per share.

We have  incurred  an  aggregate  of  approximately  $1,020,226  of  expenses in
connection  with the  offering,  including  underwriting  discounts  ($708,750),
expenses paid to or for the  underwriter  ($157,500),  and other expenses of the
offering  ($153,976).  Such amounts were not paid  directly or indirectly to the
directors,  the  officers  or to persons  owning 10% or more of any class of our
equity  securities or to our affiliates.  Rather,  such payments were to others.
After  deducting  the total  expenses,  we  received  net  offering  proceeds of
approximately  $6,854,774.  Through November 12, 2003, the net offering proceeds
have been used for:


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         o        $3,452,464 million to reduce indebtedness;

         o        $472,282 for the  manufacture of gas  compressors to be placed
                  in our rental fleet and leased over the next one to two years;
                  and

         o        $2,930,028 in temporary investments.

None of the net offering  proceeds were used to make payments to the  directors,
the  officers  or to  persons  owning  10% or more of any  class  of our  equity
securities or to any affiliates. Rather such payments were to others.

Our uses of the net  proceeds do not  represent a material  change in the use of
proceeds described in our prospectus.


Item 6.  Exhibits and Reports on Form 8-K

         (a)      Exhibits

                  99.1     Certification of Chief Executive  Officer Pursuant to
                           18 U.S.C. Section 1350

                  99.2     Certification of Chief Financial  Officer Pursuant to
                           18 U.S.C. Section 1350

         (b)      Reports on Form 8-K

                  None.


SIGNATURES

In accordance with the  requirements of the Exchange Act, the registrant  caused
this  report to be  signed on its  behalf  by the  undersigned,  thereunto  duly
authorized.


NATURAL GAS SERVICES GROUP, INC.


By: /s/ Wayne L. Vinson
   -----------------------------
   Wayne L. Vinson
   President and Chief Executive
   Officer

By: /s/ Earl R. Wait
   -----------------------------
   Earl R. Wait
   Chief Financial Officer
   and Treasurer

December 2, 2002



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                        NATURAL GAS SERVICES GROUP, INC.

                                  CERTIFICATION


         I, Wayne L. Vinson, certify that:

         1. I have reviewed this quarterly  report on Form 10-QSB of Natural Gas
Services Group, Inc.;

         2. Based on my knowledge,  this  quarterly  report does not contain any
untrue  statement of a material fact or omit to state a material fact  necessary
to make the  statements  made,  in light of the  circumstances  under which such
statements  were made, not misleading with respect to the period covered by this
quarterly report;

         3. Based on my knowledge, the financial statements, and other financial
information  included in this quarterly  report,  fairly present in all material
respects the financial  condition,  results of operations  and cash flows of the
registrant as of, and for, the periods presented in this quarterly report;

         4. The registrant's other certifying officers and I are responsible for
establishing and maintaining  disclosure  controls and procedures (as defined in
Exchange Act Rules 13a-14 and 15d-14) for the registrant and have:

         (a) designed  such  disclosure  controls and  procedures to ensure that
         material  information   relating  to  the  registrant,   including  its
         consolidated  subsidiaries,  is made known to us by others within those
         entities, particularly during the period in which this quarterly report
         is being prepared;

         (b) evaluated the effectiveness of the registrant's disclosure controls
         and  procedures as of a date within 90 days prior to the filing date of
         this quarterly report (the "Evaluation Date"); and

         (c)  presented  in this  quarterly  report  our  conclusions  about the
         effectiveness  of the disclosure  controls and procedures  based on our
         evaluation as of the Evaluation Date;

         5. The  registrant's  other  certifying  officers and I have disclosed,
based on our most recent evaluation,  to the registrant's auditors and the audit
committee  of  registrant's  board  of  directors  (or  persons  performing  the
equivalent functions):

         (a) all significant deficiencies in the design or operation of internal
         controls  which  could  adversely  affect the  registrant's  ability to
         record,   process,   summarize  and  report  financial  data  and  have
         identified  for the  registrant's  auditors any material  weaknesses in
         internal controls; and

         (b) any fraud,  whether or not material,  that  involves  management or
         other  employees  who  have a  significant  role  in  the  registrant's
         internal controls; and

         6. The registrant's  other certifying  officers and I have indicated in
this quarterly report whether or not there were significant  changes in internal
controls or in other factors that could  significantly  affect internal controls
subsequent to the date of our most recent  evaluation,  including any corrective
actions with regard to significant deficiencies and material weaknesses.


Date: December 2, 2002                           /s/ Wayne L. Vinson
                                                --------------------------------
                                                Wayne L. Vinson
                                                Title:   Chief Executive Officer



                                       5


                        NATURAL GAS SERVICES GROUP, INC.

                                  CERTIFICATION

         I, Earl R. Wait, certify that:

         1. I have reviewed this quarterly  report on Form 10-QSB of Natural Gas
Services Group, Inc.;

         2. Based on my knowledge,  this  quarterly  report does not contain any
untrue  statement of a material fact or omit to state a material fact  necessary
to make the  statements  made,  in light of the  circumstances  under which such
statements  were made, not misleading with respect to the period covered by this
quarterly report;

         3. Based on my knowledge, the financial statements, and other financial
information  included in this quarterly  report,  fairly present in all material
respects the financial  condition,  results of operations  and cash flows of the
registrant as of, and for, the periods presented in this quarterly report;

         4. The registrant's other certifying officers and I are responsible for
establishing and maintaining  disclosure  controls and procedures (as defined in
Exchange Act Rules 13a-14 and 15d-14) for the registrant and have:

         (a) designed  such  disclosure  controls and  procedures to ensure that
         material  information   relating  to  the  registrant,   including  its
         consolidated  subsidiaries,  is made known to us by others within those
         entities, particularly during the period in which this quarterly report
         is being prepared;

         (b) evaluated the effectiveness of the registrant's disclosure controls
         and  procedures as of a date within 90 days prior to the filing date of
         this quarterly report (the "Evaluation Date"); and

         (c)  presented  in this  quarterly  report  our  conclusions  about the
         effectiveness  of the disclosure  controls and procedures  based on our
         evaluation as of the Evaluation Date;

         5. The  registrant's  other  certifying  officers and I have disclosed,
based on our most recent evaluation,  to the registrant's auditors and the audit
committee  of  registrant's  board  of  directors  (or  persons  performing  the
equivalent functions):

         (a) all significant deficiencies in the design or operation of internal
         controls  which  could  adversely  affect the  registrant's  ability to
         record,   process,   summarize  and  report  financial  data  and  have
         identified  for the  registrant's  auditors any material  weaknesses in
         internal controls; and

         (b) any fraud,  whether or not material,  that  involves  management or
         other  employees  who  have a  significant  role  in  the  registrant's
         internal controls; and

         6. The registrant's  other certifying  officers and I have indicated in
this quarterly report whether or not there were significant  changes in internal
controls or in other factors that could  significantly  affect internal controls
subsequent to the date of our most recent  evaluation,  including any corrective
actions with regard to significant deficiencies and material weaknesses.


Date: December 2, 2002                           /s/ Earl R. Wait
                                                --------------------------------
                                                Earl R. Wait
                                                Title:   Chief Financial Officer


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                                  EXHIBIT INDEX

Exhibit 99.1      Certification of Chief Executive Officer Pursuant to 18 U.S.C.
                  Section 1350

Exhibit 99.2      Certification of Chief Financial Officer Pursuant to 18 U.S.C.
                  Section 1350
































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