SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT

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

         Date of Report (Date of earliest event reported): December 13, 2001

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

           PENNSYLVANIA            1-13045              23-2588479
  State or other jurisdiction    (Commission       (IRS Employer
       of incorporation)         File Number)      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   December   6,   2001,   Iron   Mountain    Incorporated    (the
"Company") announced  the  authorization and  approval of a 3-for-2  stock split
effected in the form of a dividend on the Company's Common Stock, par value $.01
per share.  Shares of the Common Stock will be issued on December  31, 2001,  to
all stockholders of record as of the close of business on December 17, 2001. The
payment date is December 31, 2001. For more information, see the Company's press
release, dated December 6, 2001, which is attached herewith as Exhibit 99.


ITEM 7. PRO FORMA FINANCIAL INFORMATION

(b) Pro Forma Financial Information

         The primary  purpose of this Form 8-K is to file pro forma  information
for the  nine  months  ended  September  30,  2001.  The pro  forma  information
presented  below  was  prepared  as if the  Company's  issuance  of and  sale of
$435,000,000 of 8-5/8% Senior  Subordinated Notes due 2013 (the "Debt Issuance")
and the redemption of the  $165,000,000  10-1/8% Senior  Subordinated  Notes due
2006 and the $130,000,000 11-1/8% Senior  Subordinated Notes due 2006 (the "Debt
Redemptions")  had  occurred on January 1, 2000.  Please see the  Liquidity  and
Capital  Resources  section of our Quarterly  Report on Form 10-Q for the period
ended September 30, 2001 for a more complete description of these transactions.

         The  historical  statement  of  operations  for the nine  months  ended
September 30, 2001,  previously filed in the Company's Form 10-Q for the quarter
ended  September  30,  2001,  does not include the pro forma  impact of the Debt
Issuance and Debt Redemptions.  The pro forma impact on the Company's historical
statement of operations as of September 30, 2001 would be a decrease in interest
expense and net loss before extraordinary item of $0.3 million and $0.2 million,
respectively.  The  pro  forma  impact  on the  Company's  balance  sheet  as of
September 30, 2001 would be a decrease in cash of $17.5  million,  a decrease in
accrued  expenses  of $9.1  million  and a decrease  in  long-term  debt of $8.3
million, representing the payment of principal, call premium and interest on the
untendered  portion  of the  10-1/8%  Senior  Subordinated  Notes  due 2006 that
occurred on October 19, 2001.


(c)  Exhibits.

EXHIBIT NO.     ITEM


   99            Press Release, dated December 6, 2001.






                                  SIGNATURES

       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

                                   (Registrant)

Date: December 13, 2001
                                       By: /s/ John F. Kenny, Jr.
                                       Name:  John F. Kenny, Jr.
                                       Title: Executive Vice President
                                              and Chief Financial Officer