EXHIBIT 99.1



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



           NOT FILED PURSUANT TO THE SECURITIES EXCHANGE ACT OF 1934



In connection with the Annual Report of Patterson-UTI Energy, Inc. (the
"Company") on Form 10-K for the period ending December 31, 2002, as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), Cloyce
A. Talbott, Chief Executive Officer, and Jonathan D. Nelson, Chief Financial
Officer, of the Company, each certify, pursuant to 18 U.S.C. Section 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/ CLOYCE A. TALBOTT
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Cloyce A. Talbott
Chief Executive Officer
February 7, 2003



/s/ JONATHAN D. NELSON
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Jonathan D. Nelson
Chief Financial Officer
February 7, 2003