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 (Date of earliest event reported): May 27, 2004

                           IRON MOUNTAIN INCORPORATED
             (Exact name of registrant as specified in its charter)

                 (State or other jurisdiction of incorporation)

                               1-13045 23-2588479
           (Commission File Number) (IRS Employer Identification No.)

                               745 Atlantic Avenue
                           Boston, Massachusetts 02111
          (Address of principal executive offices, including zip code)

                                 (617) 535-4766
              (Registrant's telephone number, including area code)

Item 5. Other Events.

      On May 27, 2004, Iron Mountain Incorporated (the "Company") announced the
authorization and approval of a three-for-two stock split effected in the form
of a dividend on the Company's Common Stock, par value $0.01 per share. Shares
of the Common Stock will be issued on June 30, 2004, to all stockholders of
record as of the close of business on June 15, 2004. For more information, see
the Company's press release, dated May 27, 2004, which is attached herewith as
Exhibit 99

Item 7. Financial Information and Exhibits.

(c) Exhibits.

99                Press release dated May 27, 2004.


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

                                                     IRON MOUNTAIN INCORPORATED

                                                 By: /s/ Jean A. Bua
                                                     Name: Jean A. Bua
                                                     Title: Vice President and
                                                            Corporate Controller

Date: May 27, 2004