W.R. Grace & Co. (GRA) 10-Q 2005 Q2 Quarterly report

                                                                      EXHIBIT 32

        CERTIFICATION UNDER SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section
1350), the undersigned certifies that (1) this Quarterly Report of W. R. Grace &
Co. (the "Company") on Form 10-Q for the period ended June 30, 2005, as filed
with the Securities and Exchange Commission on the date hereof (this "Report"),
fully complies with the requirements of Sections 13(a) or 15(d) of the
Securities Exchange Act of 1934, as amended, and (2) the information contained
in this Report fairly presents, in all material respects, the financial
condition and results of operations of the Company.


/s/ A. E. Festa
- ----------------------------------------
President and Chief Executive Officer


/s/ Robert M. Tarola
- ----------------------------------------
Senior Vice President and Chief
Financial Officer

Date: August 8, 2005

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