EXHIBIT 99.3

Certification of Principal Financial Officer
Pursuant to 18 U.S.C. 1350
(Section 906 of the Sarbanes-Oxley Act of 2002)

        I, Barry Lefkowitz, Chief Financial Officer of Mack-Cali Realty Corporation (the "Registrant"), do hereby certify, pursuant to 18 U.S.C. Section 1350 as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge, based upon a review of the Quarterly Report on Form 10-Q for the period ended September 30, 2002 of the Registrant, as filed with the Securities and Exchange Commission on the date hereof (the "Report"):

(1)

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(2)

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

November 4, 2002