Meadwestvaco (MWV) 10-Q 2005 Q2 Quarterly report

Exhibit 32.2

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

The undersigned hereby certifies, in his capacity as an officer of MeadWestvaco Corporation (the “Company”), for purposes of 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

• the Quarterly Report of the Company on Form 10-Q for the period ended June 30, 2005 fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934; and

• the information contained in such report fairly presents, in all material respects, the financial condition and results of operation of the Company.

Date: August 4, 2005

/s/ E. Mark Rajkowski

E. Mark Rajkowski

Senior Vice President and

Chief Financial Officer