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


                                    FORM 8-K


                 CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934


       Date of Report (Date of earliest event reported): October 18, 2004


                        NATURAL GAS SERVICES GROUP, INC.
             (Exact Name of Registrant as Specified in Its Charter)



            Colorado                      1-31398                75-2811855
  (State or other jurisdiction        (Commission File         (IRS Employer
of  Incorporation or organization)         Number)           Identification No.)




2911 South County Road 1260 Midland, Texas                          79706
 (Address of Principal Executive Offices)                         (Zip Code)


                                  432-563-3974
              (Registrant's telephone number, including area code)


                                 Not Applicable
          (Former name or former address, if changed since last report)



Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

[_]      Written  communications  pursuant to Rule 425 under the  Securities Act
         (17 CFR 230.425)

[_]      Soliciting  material pursuant to Rule 14a-12 under the Exchange Act (17
         CFR 240.14a-12)

[_]      Pre-commencement  communications  pursuant to Rule  14d-2(b)  under the
         Exchange Act (17 CFR 240.14d-2(b))

[_]      Pre-commencement  communications  pursuant to Rule  13e-4(c)  under the
         Exchange Act (17 CFR 240.13e-4(c))




Item 1.01.  Entry into a Material Definitive Agreement.

         On October 18, 2004,  Natural Gas Services Group,  Inc.  entered into a
Stock Purchase Agreement with Screw Compression Systems, Inc., or "SCS", and the
stockholders of SCS. Under this agreement,  Natural Gas Services Group agreed to
purchase  from Paul D.  Hensley,  Tony  Vohjesus and Jim  Hazlett,  the "selling
stockholders", all of the outstanding shares of capital stock of SCS.

         SCS is a privately owned manufacturer of natural gas compressors,  with
its principal offices located in Tulsa, Oklahoma.

         The selling  stockholders will receive, in proportionate  shares (based
on their stock ownership of SCS), a total of $15 million, consisting of:

         o        $8 million in cash;

         o        promissory  notes  issued  by  Natural  Gas  Services  in  the
                  aggregate  principal  amount of $3 million bearing interest at
                  the rate of four  percent  (4.00%) per annum,  maturing  three
                  years  from the date of  closing  and  secured  by a letter of
                  credit in the face amount of $2 million; and

         o        609,576 shares of Natural Gas Services  common stock valued at
                  $4 million,  based on the average of the daily closing  prices
                  of the common  stock for the ninety  consecutive  trading days
                  ended April 28, 2004. All of the shares,  upon issuance,  will
                  be  "restricted"  securities  within  the  meaning of Rule 144
                  under the Securities Act of 1933, as amended,  and will bear a
                  legend to that effect.

         Under terms of the agreement,  for a period of two years  following the
closing,  the  selling  stockholders  will have the  right,  subject  to certain
limitations,  to include  or  "piggyback"  the  609,576  shares of common  stock
received  by them in the  transaction  in any  registration  statement  filed by
Natural Gas Services with the Securities and Exchange Commission.

         After the closing, SCS will be operated as a wholly owned subsidiary of
Natural Gas Services and the selling stockholders will continue in their present
positions  with SCS under  three-year  employment  agreements.  In addition,  at
closing,  Paul D. Hensley  will be  appointed to fill a vacancy  existing on the
Board of Directors of Natural Gas Services, to hold office until the next annual
meeting of  stockholders of Natural Gas Services at which directors are elected,
and in  connection  with the next annual  meeting of  stockholders,  Natural Gas
Services will nominate Paul D. Hensley for election as a director to serve for a
term the same as the class of directors then standing for election.

         Natural  Gas  Services  has  agreed to pay to  Karifico  Consultants  a
finder's fee in the amount of $150,000.

         The agreement is subject to customary closing conditions, including the
approval by the American Stock Exchange of the common stock for listing on AMEX.
Closing  under the  agreement is  scheduled to occur not later than  December 6,
2004. The agreement may be terminated by the selling stockholders or Natural Gas
Services Group if the closing does not occur by December 6, 2004.



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         Natural Gas Services Group has no material relationship with SCS or the
selling stockholders other then with respect to the Stock Purchase Agreement.

         The foregoing is a summary of the material  features of the  agreement.
This summary does not purport to be complete and is qualified in its entirety by
reference to the terms of the agreement,  which is filed as Exhibit 10.1 to this
Current Report on Form 8-K, and incorporated herein by reference.






















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Item 9.01.  Financial Statements and Exhibits.

         (c)      Exhibits

         The Exhibit  listed  below is filed as part of this  Current  Report on
Form 8-K.

                  Exhibit No.       Description
                  -----------       -----------

                     4.1            Stock Purchase Agreement,  dated October 18,
                                    2004,  by and  among  Natural  Gas  Services
                                    Group,  Inc.,  Screw  Compression   Systems,
                                    Inc., Paul D. Hensley,  Jim Hazlett and Tony
                                    Vohjesus












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                                   SIGNATURES

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
the  Registrant  has duly  caused  this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                        NATURAL GAS SERVICES GROUP, INC.


                                               By:  /s/ Wallace C. Sparkman    
                                                  ------------------------------
                                                  Wallace C. Sparkman, President


Dated:  October 20, 2004



















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                                  EXHIBIT INDEX



Exhibit No.                                    Description             
-----------                                    -----------             

   4.1                     Stock Purchase Agreement,  dated October 18, 2004, by
                           and among  Natural Gas Services  Group,  Inc.,  Screw
                           Compression  Systems,  Inc.,  Paul  D.  Hensley,  Jim
                           Hazlett and Tony Vohjesus



















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