Exhibit No. (99.1) Certification of Chief Executive Officer ---------------------------------------- Pursuant to Section 1350 of Chapter 63 of the United States Code ---------------------------------------------------------------- I, Thomas J. Falk, Chief Executive Officer of Kimberly-Clark Corporation, certify that to the best of my knowledge: (1) the Form 10-K, filed with the Securities and Exchange Commission on March 14, 2003 ("accompanied 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 accompanied report fairly presents, in all material respects, the financial condition and results of operations of Kimberly-Clark Corporation. /s/ Thomas J. Falk --------------------------------- Thomas J. Falk Chief Executive Officer March 14, 2003