EXHIBIT 99.1


I, Merrill A. Miller, Jr., Chairman, President and Chief Executive Officer of
National-Oilwell, Inc., certify, pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that:

     (1)  the Annual Report on Form 10-K/A for the year ended December 31, 2002
          (the "Periodic Report') which this statement accompanies fully
          complies with the requirements of Section 13(a) of the Securities
          Exchange Act of 1934 (15 U.S.C. 78m) and

     (2)  information contained in the Periodic Report fairly presents, in all
          material respects, the financial condition and results of operations
          of National-Oilwell, Inc.


Dated: June 26, 2003

                               /s/ Merrill A. Miller, Jr.
                               -------------------------------------------------
                               Merrill A. Miller, Jr.
                               Chairman, President and Chief Executive Officer

A signed original of this written statement required by Section 906 has been
provided to National-Oilwell, Inc. and will be retained by National-Oilwell,
Inc. and furnished to the Securities and Exchange Commission or its staff upon
request.