As filed with the Securities and Exchange Commission on August 7, 1998
                                                   Registration No. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                 --------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                  ------------

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

                               Delaware 04-3107342
                (State or other jurisdiction of (I.R.S. Employer
               incorporation or organization) Identification No.)


                745 Atlantic Avenue, Boston, Massachusetts 02111
                                 (617) 357-4455
           (Address of Principal Executive Offices including zip code)
                                  -------------

              Iron Mountain Incorporated 1995 Stock Incentive Plan
                            (Full titles of the plan)
                                  ------------

                                C. Richard Reese
                            Chairman of The Board of
                      Directors and Chief Executive Officer
                           Iron Mountain Incorporated
                               745 Atlantic Avenue
                           Boston, Massachusetts 02111
                                 (617) 357-4455
            (Name, address and telephone number of agent for service)
                                  -------------

                                    Copy to:
                             William J. Curry, Esq.
                            Sullivan & Worcester LLP
                             One Post Office Square
                           Boston, Massachusetts 02109
                                 (617) 338-2800
                                ----------------

 If, as a result of stock splits, stock dividends or similar transactions, the
 number of securities purported to be registered on this Registration Statement
      changes, the provisions of Rule 416 shall apply to this Registration
                                   Statement.

 The prospectus meeting the requirements of Section 10(a) of the Securities Act
    of 1933, as amended, which is being provided to participants in the 1995
      Stock Incentive Plan in conjunction with this Registration Statement
          also relates to the shares registered under the Registration
          Statement on Form S-8 dated April 9, 1997 (File No. 333-24803
              and the Registration Statement on Form S-8 dated August 8,
            1998 (File No. 333-33191) of Iron Mountain Incorporated.


<PAGE>




<TABLE>
<CAPTION>
                                                  ---------------

                                          CALCULATION OF REGISTRATION FEE


                                                        Proposed            Proposed Maximum
  Title of Securities         Amount to be          Maximum Offering            Aggregate               Amount of
   to be Registered            Registered          Price Per Share(1)       Offering Price(1)        Registration Fee
   ----------------            ----------          ------------------       -----------------        ----------------
<S>                              <C>                   <C>                    <C>                      <C>     
Common Stock, par
value $.01 per share             900,000                $27.875                $25,087,500              $7,400.81


<FN>
(1)      With respect to the additional  900,000 shares  issuable under the 1995
         Stock Incentive Plan, the proposed maximum offering price per share and
         the  proposed  maximum  aggregate  offering  price have been  estimated
         solely for purpose of calculating the amount of the registration fee in
         accordance  with Rules  457(c) and 457(h) under the  Securities  Act of
         1933,  as  amended,  on the  basis of the  average  of the high and low
         prices of the Common Stock on the Nasdaq National Market  ("Nasdaq") on
         August 5, 1998.  944,903 shares issuable under the 1995 Stock Incentive
         Plan were registered under the Registrant's  Registration  Statement on
         Form S-8 (File No.  333-24803),  filed  with  Securities  and  Exchange
         Commission  (the  "Commission")  on April 9,  1997 and a filing  fee of
         $4,425.28  was  paid on such  date  with  respect  to such  shares.  An
         additional  400,000 shares issuable under the 1995 Stock Incentive Plan
         were registered under the Registrant's  Registration  Statement on Form
         S-8 (File No.  333-33191),  filed with the Commission on August 8, 1997
         and a filing  fee of  $3,803.03  was paid on such date with  respect to
         such shares.
</FN>
</TABLE>



<PAGE>



PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

         Insofar as additional securities are being registered of the same class
as other  securities  for  which a  registration  statement  filed on this  form
relating to an employee  benefit plan is effective,  in accordance  with General
Instruction  E  to  the  Registration  Statement  on  Form  S-8,  Iron  Mountain
Incorporated  (the "Company")  hereby  incorporates by reference the contents of
the Company's  Registration  Statement on Form S-8 dated April 9, 1997 (File No.
333-24803) and the Company's  Registration Statement on Form S-8 dated August 8,
1998 (File No.  333- 33191) and omits the  information  required by Part II from
this  Registration  Statement,  other than Item 3 and Item 8, below,  which have
been updated.

Item 3.  Incorporation of Documents by Reference.

         The Company previously registered under the Securities Act an aggregate
of 944,903 shares of Common Stock offered  pursuant to the 1995 Stock  Incentive
Plan pursuant to a Registration Statement on Form S-8 (File No. 333-24803) filed
with the Commission on April 9, 1997, and 400,000 shares of Common Stock offered
pursuant to the 1995 Stock  Incentive Plan pursuant to a Registration  Statement
on Form S-8 (File No.  333-33191)  filed with the  Commission on August 8, 1998,
both of which are incorporated in this Registration Statement by reference.

         The  following  additional  documents,  which  have  been  filed by the
Company with the Commission, are incorporated by reference in and made a part of
this Registration Statement, as of their respective dates:

         (a)      The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended March 31, 1998;

         (b)      The  Company's  Annual Report on Form 10-K for the fiscal year
                  ended December 31, 1997;

         (c)      The  Company's  Current  Report on Form 8-K dated  August  7,
                  1998;

         (d)      The Company's Current Report on Form 8-K dated July 10, 1998;

         (e)      The Company's Current Report on Form 8-K dated April 21, 1998;

         (f)      The Company's Current Report on Form 8-K dated April 7, 1998;

         (g)      The Company's Current Report on Form 8-K dated March 30, 1998;

         (h)      The Company's Current Report on Form 8-K dated March 9, 1998;

         (i)      The Company's  Current  Report on Form 8-K dated  February 18,
                  1998;

         (j)      The  Company's  Current  Report on Form 8-K dated  January  6,
                  1998; and

         (k)      The description of the Common Stock contained in the Company's
                  registration  statement  on Form 8-A dated  January  18,  1996
                  (File No. 0-27584),  including any amendments or reports filed
                  for the purpose of updating such description.

         All documents  subsequently  filed by the Company  pursuant to Sections
13(a),  13(c), 14 and 15(d) of the Securities  Exchange Act of 1934, as amended,
prior to the  filing of a  post-effective  amendment  which  indicates  that all
securities  offered  have been sold or which  deregisters  all  securities  then
remaining  unsold,  shall be  deemed to be  incorporated  by  reference  in this
Registration  Statement  and to be part  hereof  from the date of filing of such
documents.

         Any  statement  contained  in a document  incorporated  or deemed to be
incorporated  by reference  herein shall be deemed to be modified or  superseded
for  purposes  of this  Registration  Statement  to the extent  that a statement
herein,  or in any subsequently  filed document which also is or is deemed to be
incorporated by reference,  modifies or supersedes such statement. Any statement
so  modified  or  superseded  shall  not be  deemed,  except as so  modified  or
superseded, to constitute a part of this Registration Statement.


                                     II - 1


<PAGE>



Item 8.  Exhibits.
                                  EXHIBIT INDEX

    Exhibit No.   Description

         5        Opinion of Sullivan & Worcester LLP.*

         23.1     Consent of Sullivan & Worcester LLP  (contained in the opinion
                  of Sullivan & Worcester LLP filed herewith as Exhibit 5).

         23.2     Consent of Arthur Andersen LLP.*

         23.3     Consent of Carbis Walker & Associates, LLP.*

         24       Power  of  Attorney   (included  in  signature  page  of  this
                  Registration Statement).

*Filed herewith.



                                     II - 2


<PAGE>



                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the Company
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of Boston, Commonwealth of Massachusetts, on the 7th day
of August, 1998.

                                   IRON MOUNTAIN INCORPORATED



                                   By: /s/ C. Richard Reese
                                       C. Richard Reese
                                       Chairman of the Board,
                                       Chief Executive Officer and Director

         The undersigned  Officers and Directors of the Company hereby severally
constitute C. Richard Reese,  John F. Kenny, Jr. and David S. Wendell,  and each
of them acting singly,  our true and lawful  attorneys to sign for us and in our
names in the  capacities  indicated  below any  amendments to this  Registration
Statement on Form S-8 (including any  post-effective  amendments  hereto) and to
file  the  same,  with  Exhibits  thereto  and  other  documents  in  connection
therewith,  with the Commission,  granting unto each of said  attorneys,  acting
singly,  full power and authority to do and perform each and every act and thing
requisite  or necessary  to be done in and about the  premises,  as fully to all
intents and  purposes as he might or could do in person,  hereby  ratifying  and
confirming  our  signatures to said  amendments to this  Registration  Statement
signed by our said  attorneys  and all else that said  attorneys may lawfully do
and cause to be done by virtue hereof.

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement has been signed below by the following persons on behalf
of the Company in the capacities indicated on the 7th day of August, 1998.


        Signatures                           Title


        /s/ C. Richard Reese
        C. Richard Reese                Chairman, Chief
                                        Executive Officer and Director


        /s/ David S. Wendell
        David S. Wendell                President, Chief Operating Officer and
                                        Director


        /s/ John F. Kenny, Jr.
        John F. Kenny, Jr.              Executive Vice President and
                                        Chief Financial Officer


        /s/ Eugene B. Doggett
        Eugene B. Doggett               Director








                                     II - 3


<PAGE>





        /s/ Constantin R. Boden
        Constantin R. Boden             Director



        /s/ Arthur D. Little
        Arthur D. Little                Director



        /s/ Vincent J. Ryan
        Vincent J. Ryan                 Director



        /s/ B. Thomas Golisano
        B. Thomas Golisano              Director



        /s/ Kent P. Dauten
        Kent P. Dauten                  Director



        /s/ Clarke H. Bailey
        Clarke H. Bailey                Director



        /s/ Jean A. Bua
        Jean A. Bua                     Vice President and Corporate
                                        Controller





                                     II - 4
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 13175}]
{"company-data": {"conformed-name": "IRON MOUNTAIN INC /DE", "cik": "0001004317", "assigned-sic": "4220", "irs-number": "043107342", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-60919", "film-number": "98679550"}, "business-address": {"street1": "745 ATLANTIC AVE", "city": "BOSTON", "state": "MA", "zip": "02111", "phone": "6173574455"}, "mail-address": {"street1": "745 ATLANTIC AVENUE", "street2": "7TH FLOOR", "city": "BOSTON", "state": "MA", "zip": "02111"}}
As filed with the Securities and Exchange Commission on August 7, 1998
                                                   Registration No. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                 --------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                  ------------

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

                               Delaware 04-3107342
                (State or other jurisdiction of (I.R.S. Employer
               incorporation or organization) Identification No.)

                745 Atlantic Avenue, Boston, Massachusetts 02111
                                 (617) 357-4455
           (Address of Principal Executive Offices including zip code)
                                  -------------

              Iron Mountain Incorporated 1995 Stock Incentive Plan
                            (Full titles of the plan)
                                  ------------

                                C. Richard Reese
                            Chairman of The Board of
                      Directors and Chief Executive Officer
                           Iron Mountain Incorporated
                               745 Atlantic Avenue
                           Boston, Massachusetts 02111
                                 (617) 357-4455
            (Name, address and telephone number of agent for service)
                                  -------------

                                    Copy to:
                             William J. Curry, Esq.
                            Sullivan & Worcester LLP
                             One Post Office Square
                           Boston, Massachusetts 02109
                                 (617) 338-2800
                                ----------------

 If, as a result of stock splits, stock dividends or similar transactions, the
 number of securities purported to be registered on this Registration Statement
      changes, the provisions of Rule 416 shall apply to this Registration
                                   Statement.

 The prospectus meeting the requirements of Section 10(a) of the Securities Act
    of 1933, as amended, which is being provided to participants in the 1995
      Stock Incentive Plan in conjunction with this Registration Statement
          also relates to the shares registered under the Registration
          Statement on Form S-8 dated April 9, 1997 (File No. 333-24803
              and the Registration Statement on Form S-8 dated August 8,
            1998 (File No. 333-33191) of Iron Mountain Incorporated.
---------------

                                          CALCULATION OF REGISTRATION FEE

                                                        Proposed            Proposed Maximum
  Title of Securities         Amount to be          Maximum Offering            Aggregate               Amount of
   to be Registered            Registered          Price Per Share(1)       Offering Price(1)        Registration Fee
   ----------------            ----------          ------------------       -----------------        ----------------
Common Stock, par
value $.01 per share             900,000                $27.875                $25,087,500              $7,400.81
(1)      With respect to the additional  900,000 shares  issuable under the 1995
         Stock Incentive Plan, the proposed maximum offering price per share and
         the  proposed  maximum  aggregate  offering  price have been  estimated
         solely for purpose of calculating the amount of the registration fee in
         accordance  with Rules  457(c) and 457(h) under the  Securities  Act of
         1933,  as  amended,  on the  basis of the  average  of the high and low
         prices of the Common Stock on the Nasdaq National Market  ("Nasdaq") on
         August 5, 1998.  944,903 shares issuable under the 1995 Stock Incentive
         Plan were registered under the Registrant's  Registration  Statement on
         Form S-8 (File No.  333-24803),  filed  with  Securities  and  Exchange
         Commission  (the  "Commission")  on April 9,  1997 and a filing  fee of
         $4,425.28  was  paid on such  date  with  respect  to such  shares.  An
         additional  400,000 shares issuable under the 1995 Stock Incentive Plan
         were registered under the Registrant's  Registration  Statement on Form
         S-8 (File No.  333-33191),  filed with the Commission on August 8, 1997
         and a filing  fee of  $3,803.03  was paid on such date with  respect to
         such shares.
PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

         Insofar as additional securities are being registered of the same class
as other  securities  for  which a  registration  statement  filed on this  form
relating to an employee  benefit plan is effective,  in accordance  with General
Instruction  E  to  the  Registration  Statement  on  Form  S-8,  Iron  Mountain
Incorporated  (the "Company")  hereby  incorporates by reference the contents of
the Company's  Registration  Statement on Form S-8 dated April 9, 1997 (File No.
333-24803) and the Company's  Registration Statement on Form S-8 dated August 8,
1998 (File No.  333- 33191) and omits the  information  required by Part II from
this  Registration  Statement,  other than Item 3 and Item 8, below,  which have
been updated.

Item 3.  Incorporation of Documents by Reference.

         The Company previously registered under the Securities Act an aggregate
of 944,903 shares of Common Stock offered  pursuant to the 1995 Stock  Incentive
Plan pursuant to a Registration Statement on Form S-8 (File No. 333-24803) filed
with the Commission on April 9, 1997, and 400,000 shares of Common Stock offered
pursuant to the 1995 Stock  Incentive Plan pursuant to a Registration  Statement
on Form S-8 (File No.  333-33191)  filed with the  Commission on August 8, 1998,
both of which are incorporated in this Registration Statement by reference.

         The  following  additional  documents,  which  have  been  filed by the
Company with the Commission, are incorporated by reference in and made a part of
this Registration Statement, as of their respective dates:

         (a)      The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended March 31, 1998;

         (b)      The  Company's  Annual Report on Form 10-K for the fiscal year
                  ended December 31, 1997;

         (c)      The  Company's  Current  Report on Form 8-K dated  August  7,
                  1998;

         (d)      The Company's Current Report on Form 8-K dated July 10, 1998;

         (e)      The Company's Current Report on Form 8-K dated April 21, 1998;

         (f)      The Company's Current Report on Form 8-K dated April 7, 1998;

         (g)      The Company's Current Report on Form 8-K dated March 30, 1998;

         (h)      The Company's Current Report on Form 8-K dated March 9, 1998;

         (i)      The Company's  Current  Report on Form 8-K dated  February 18,
                  1998;

         (j)      The  Company's  Current  Report on Form 8-K dated  January  6,
                  1998; and

         (k)      The description of the Common Stock contained in the Company's
                  registration  statement  on Form 8-A dated  January  18,  1996
                  (File No. 0-27584),  including any amendments or reports filed
                  for the purpose of updating such description.

         All documents  subsequently  filed by the Company  pursuant to Sections
13(a),  13(c), 14 and 15(d) of the Securities  Exchange Act of 1934, as amended,
prior to the  filing of a  post-effective  amendment  which  indicates  that all
securities  offered  have been sold or which  deregisters  all  securities  then
remaining  unsold,  shall be  deemed to be  incorporated  by  reference  in this
Registration  Statement  and to be part  hereof  from the date of filing of such
documents.

         Any  statement  contained  in a document  incorporated  or deemed to be
incorporated  by reference  herein shall be deemed to be modified or  superseded
for  purposes  of this  Registration  Statement  to the extent  that a statement
herein,  or in any subsequently  filed document which also is or is deemed to be
incorporated by reference,  modifies or supersedes such statement. Any statement
so  modified  or  superseded  shall  not be  deemed,  except as so  modified  or
superseded, to constitute a part of this Registration Statement.

                                     II - 1
Item 8.  Exhibits.
                                  EXHIBIT INDEX

    Exhibit No.   Description

         5        Opinion of Sullivan & Worcester LLP.*

         23.1     Consent of Sullivan & Worcester LLP  (contained in the opinion
                  of Sullivan & Worcester LLP filed herewith as Exhibit 5).

         23.2     Consent of Arthur Andersen LLP.*

         23.3     Consent of Carbis Walker & Associates, LLP.*

         24       Power  of  Attorney   (included  in  signature  page  of  this
                  Registration Statement).

*Filed herewith.

                                     II - 2
SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the Company
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of Boston, Commonwealth of Massachusetts, on the 7th day
of August, 1998.

                                   IRON MOUNTAIN INCORPORATED

                                   By: /s/ C. Richard Reese
                                       C. Richard Reese
                                       Chairman of the Board,
                                       Chief Executive Officer and Director

         The undersigned  Officers and Directors of the Company hereby severally
constitute C. Richard Reese,  John F. Kenny, Jr. and David S. Wendell,  and each
of them acting singly,  our true and lawful  attorneys to sign for us and in our
names in the  capacities  indicated  below any  amendments to this  Registration
Statement on Form S-8 (including any  post-effective  amendments  hereto) and to
file  the  same,  with  Exhibits  thereto  and  other  documents  in  connection
therewith,  with the Commission,  granting unto each of said  attorneys,  acting
singly,  full power and authority to do and perform each and every act and thing
requisite  or necessary  to be done in and about the  premises,  as fully to all
intents and  purposes as he might or could do in person,  hereby  ratifying  and
confirming  our  signatures to said  amendments to this  Registration  Statement
signed by our said  attorneys  and all else that said  attorneys may lawfully do
and cause to be done by virtue hereof.

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement has been signed below by the following persons on behalf
of the Company in the capacities indicated on the 7th day of August, 1998.

        Signatures                           Title

        /s/ C. Richard Reese
        C. Richard Reese                Chairman, Chief
                                        Executive Officer and Director

        /s/ David S. Wendell
        David S. Wendell                President, Chief Operating Officer and
                                        Director

        /s/ John F. Kenny, Jr.
        John F. Kenny, Jr.              Executive Vice President and
                                        Chief Financial Officer

        /s/ Eugene B. Doggett
        Eugene B. Doggett               Director

                                     II - 3
/s/ Constantin R. Boden
        Constantin R. Boden             Director

        /s/ Arthur D. Little
        Arthur D. Little                Director

        /s/ Vincent J. Ryan
        Vincent J. Ryan                 Director

        /s/ B. Thomas Golisano
        B. Thomas Golisano              Director

        /s/ Kent P. Dauten
        Kent P. Dauten                  Director

        /s/ Clarke H. Bailey
        Clarke H. Bailey                Director

        /s/ Jean A. Bua
        Jean A. Bua                     Vice President and Corporate
                                        Controller

                                     II - 4