QuickLinks -- Click here to rapidly navigate through this document

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549



FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report: February 25, 2003
(Date of earliest event reported)

MACK-CALI REALTY CORPORATION
(Exact name of Registrant as specified in its charter)

Maryland
(State or other jurisdiction of incorporation)

1-13274
(Commission File No.)
  22-3305147
(I.R.S. Employer
Identification No.)

11 Commerce Drive, Cranford, New Jersey 07016
(Address of Principal Executive Offices) (Zip Code)

(908) 272-8000
(Registrant's telephone number, including area code)

N/A
(Former Name or Former Address, if Changed Since Last Report)





Item 7.    Financial Statements, Pro Forma Financial Information and Exhibits


Exhibit Number

  Exhibit Title

99.1   Transmittal Letter
99.2   Certification of Chief Executive Officer
99.3   Certification of Chief Financial Officer


Item 9.    Regulation FD Disclosure

        On February 25, 2003, Mack-Cali Realty Corporation (the "Company") filed its Annual Report on Form 10-K for the year ended December 31, 2002 with the Securities and Exchange Commission. Accompanying the Annual Report as correspondence were the transmittal letter and certifications of the Company's Chief Executive Officer, Mitchell E. Hersh, and Chief Financial Officer, Barry Lefkowitz, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, attached as exhibits hereto.

        The transmittal letter and certifications attached as exhibits hereto are being furnished solely pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and are not being filed as part of the Company's Annual Report on Form 10-K for the year ended December 31, 2002 or as a separate disclosure document. The information included in this Current Report on Form 8-K (including the exhibits hereto) is furnished pursuant to Item 9 and shall not be deemed to be "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. This Current Report (including the exhibits hereto) will not be deemed an admission as to the materiality of any information required to be disclosed solely to satisfy the requirements of Regulation FD.

2



SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

    MACK-CALI REALTY CORPORATION

Date: February 25, 2003

 

By:

/s/  
ROGER W. THOMAS      
Roger W. Thomas
Executive Vice President, General Counsel and Secretary

3



EXHIBIT INDEX

Exhibit Number

  Exhibit Title

99.1   Transmittal Letter
99.2   Certification of Chief Executive Officer
99.3   Certification of Chief Financial Officer



QuickLinks

SIGNATURES
EXHIBIT INDEX