Exhibit 10(a)





      AMENDMENT dated as of December 12, 1993, to the Credit Agreement dated
as of September 24, 1992, (as heretofore amended, the "Agreement"), among
Parker Drilling Company, a Delaware corporation (the "Borrower"), Morgan
Guaranty Trust Company of New York ("Morgan") and Internationale Nederlanden
Bank N.V. ("ING") (individually referred to herein as a "Bank" and
collectively referred to as the "Banks").


                                  WITNESSETH:
                                  -----------

      WHEREAS, the Borrower and the Banks are parties to the Agreement
referred to above; and

      WHEREAS, the Borrower has requested that the Agreement be amended as
provided herein to clarify the definitions of Cash Equivalents and
acquisitions and to increase the limitation on investments, advances and loans
and the limitation on capital expenditures;

      WHEREAS, the parties hereto have agreed to such amendment subject to the
terms contained herein;

      NOW, THEREFORE, in consideration of the premises and the mutual
agreement herein contained, the Borrower and the Banks agree as follows:

      1.    AMENDMENT OF CASH EQUIVALENTS DEFINITION UNDER SUBSECTION 1.1. 
The definition of Cash Equivalents is hereby amended by adding the following
language at the end, 

      "and (i) 7, 28, 35 and 49 day auction rate or re-marketed taxable or    
      tax-free securities of issuers of indebtedness rated "A" or better by
      Moody's Investors Service, Inc. or "A" or better by Standard & Poor's
      Corporation;"

      2.    AMENDMENT TO SUBSECTION 6.2.  Subsection 6.2 is hereby amended by
deleting the following words in the last sentence:


      "subsequent to the date of this Agreement."

      3.    AMENDMENT OF SUBSECTION 6.8.  Subsection 6.8 is hereby amended by
deleting in subpart (i) "$30,000,000" and inserting in lieu thereof
"$50,000,000" and by adding a new subpart (iii) as follows:

      "(iii) any other capital assets acquired with treasury stock or newly
      issued stock in the Company"

      4.    EFFECTIVENESS.  This Amendment shall become effective as of the
date first written above after being executed by the Borrow and the Banks.



      5.    DEFINITIONS.  Terms defined in the Agreement shall have their
defined meanings when used herein.

      6.    EFFECT OF AMENDMENT.  Except as amended and modified by this
Amendment, the Agreement shall continue to be, and shall remain, in full force
and effect in accordance with its terms.

      7.  COUNTERPARTS.  This Amendment may be signed in any number of
counterparts, each of which shall be an original, and all of which taken
together shall constitute a single agreement with the same effect as if the
signature thereto and hereto were upon the same instrument.  This Amendment
shall become binding and enforceable upon the execution by all the parties
hereto as of the day and year first written above. 

      8.    GOVERNING LAW.  This Amendment shall be governed by, and construed
and interpreted in accordance with, the laws of the State of New York.

      IN WITNESS WHEREOF, the parties have caused this Amendment to be
executed and delivered by their respective duly authorized officers as of the
date first above written.  

                                          PARKER DRILLING COMPANY

                                          By: /s/I. E. Hendrix
                                              --------------------------
                                          Its:  Vice President



                                          MORGAN GUARANTY TRUST COMPANY
                                          OF NEW YORK

                                          By: /s/Bill Jenks
                                              --------------------------
                                          Its:  Vice President



                                          INTERNATIONAL NEDERLANDEN BANK N.V.

                                          By: /s/John T. Catchpole
                                              --------------------------
                                          Its:  Vice President