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 1998 Employee Stock Purchase 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.




<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             375,000                $27.875                $10,453,125                $3,083.67

Plan Participation
Interests                          (2)                     (2)                     (2)                     (2)


<FN>
(1)      With respect to the 375,000  shares  issuable  under the 1998  Employee
         Stock Purchase Plan (the "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.

(2)      Pursuant  to Rule  416(c),  an  indeterminate  number of  participation
         interests in the Plan are being registered. Pursuant to Rule 457(h)(2),
         no additional  filing fee is required with respect to the participation
         interests in the Plan.
</FN>
</TABLE>



<PAGE>



PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

         The  following  additional  documents,  which  have been  filed by Iron
Mountain   Incorporated   (the  "Company")  with  the  Securities  and  Exchange
Commission (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.

Item 4.  Description of Securities.

         Not applicable.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the shares  offered  hereby will be passed upon for the
Company by Sullivan & Worcester LLP,  Boston,  Massachusetts.  Jas. Murray Howe,
Secretary of the Company,  is of counsel to Sullivan & Worcester  LLP and is the
owner of 5,782 shares of Common Stock.


                                     II - 1


<PAGE>



Item 6.  Indemnification of Directors and Officers.

         Section  145 of the  Delaware  General  Corporation  Law  (the  "DGCL")
provides, in effect, that any person made a party to any action by reason of the
fact that he is or was a director, officer, employee or agent of the Company may
and, in certain cases,  must be indemnified by the Company against,  in the case
of a non-derivative  action,  judgments,  fines,  amounts paid in settlement and
reasonable expenses  (including  attorney's fees) incurred by him as a result of
such action, and in the case of a derivative action, against expenses (including
attorney's  fees),  if in either  type of action he acted in good faith and in a
manner he reasonably  believed to be in or not opposed to the best  interests of
the Company.  This  indemnification  does not apply, in a derivative  action, to
matters as to which it is adjudged that the director, officer, employee or agent
is liable to the Company, unless upon court order it is determined that, despite
such  adjudication  of liability,  but in view of all the  circumstances  of the
case, he is fairly and reasonably entitled to indemnity for expenses,  and, in a
non-derivative  action,  to any  criminal  proceeding  in which such  person had
reasonable cause to believe his conduct was unlawful.

         Article  Sixth of the  Company's  Amended and Restated  Certificate  of
Incorporation  provides that the Company shall  indemnify  each person who is or
was an officer or director of the Company to the  fullest  extent  permitted  by
Section 145 of the DGCL.

         Article  Seventh of the Company's  Amended and Restated  Certificate of
Incorporation  states that no  director  of the  Company  shall be liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a  director,  except  to the  extent  that  exculpation  from  liability  is not
permitted under the DGCL as in effect when such breach occurred.

Item 7.  Exemption from Registration Claimed.

         Not Applicable.

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.

Item 9.  Undertakings.

         (a)  The undersigned registrant hereby undertakes:

                  (1) to file,  during any  period in which  offers or sales are
         being made, a post-effective amendment to this Registration Statement:

                  (i)      to  include  any   prospectus   required  by  Section
                           10(a)(3) of the Securities Act of 1933;

                  (ii)     to  reflect  in the  prospectus  any  facts or events
                           arising after the effective date of the  Registration
                           Statement   (or  the   most   recent   post-effective
                           amendment  thereof)  which,  individually  or in  the
                           aggregate,  represent  a  fundamental  change  in the
                           information set

                                     II - 2


<PAGE>



                           forth in the Registration Statement.  Notwithstanding
                           the foregoing,  any increase or decrease in volume of
                           securities  offered  (if the  total  dollar  value of
                           securities  offered  would not exceed  that which was
                           registered)  and any  deviation  from the low or high
                           and of the estimated  maximum  offering  range may be
                           reflected  in the form of  prospectus  filed with the
                           Commission   pursuant  to  Rule  424(b)  if,  in  the
                           aggregate,  the changes in volume and price represent
                           no  more  than  20  percent  change  in  the  maximum
                           aggregate   offering   price   set   forth   in   the
                           "Calculation  of  Registration   Fee"  table  in  the
                           effective Registration Statement;

                  (iii)    to include any material  information  with respect to
                           the plan of distribution not previously  disclosed in
                           the Registration  Statement or any material change to
                           such information in the Registration Statement:

         provided,  however,  that  paragraphs  (a)(1)(i) and  (a)(1)(ii) do not
         apply if the  information  required to be included in a  post-effective
         amendment by those  paragraphs  is contained in periodic  reports filed
         with or  furnished  to the  Commission  by the  registrant  pursuant to
         Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that
         are incorporated by reference in the Registration Statement;

                  (2) that, for the purpose of determining  any liability  under
         the Securities Act of 1933, each such post-effective amendment shall be
         deemed to be a new  Registration  Statement  relating to the securities
         offered therein, and the offering of such securities at that time shall
         be deemed to be the initial bona fide offering thereof; and

                  (3) to remove from  registration by means of a  post-effective
         amendment any of the securities being registered which remain unsold at
         the termination of the offering;

         (b) The undersigned  registrant hereby undertakes that, for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  Act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
Registration  Statement  shall  be  deemed  to be a new  Registration  Statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof; and

         (c)  Insofar  as  indemnification  for  liabilities  arising  under the
Securities Act of 1933 may be permitted to directors,  officers and  controlling
persons of the registrant  pursuant to the foregoing  provisions,  or otherwise,
the  registrant  has been  advised  that in the  opinion of the  Securities  and
Exchange  Commission such  indemnification is against public policy as expressed
in that Act and is,  therefore,  unenforceable.  In the  event  that a claim for
indemnification  against  such  liabilities  (other  than  the  payment  by  the
registrant of expenses  incurred or paid by a director,  officer or  controlling
person of the  registrant  in the  successful  defense  of any  action,  suit or
proceeding)  is  asserted by such  director,  officer or  controlling  person in
connection with the securities being registered,  the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit  to a  court  of  appropriate  jurisdiction  the  question  whether  such
indemnification  by it is against  public policy as expressed in the  Securities
Act of 1933 and will be governed by the final adjudication of such issue.


                                     II - 3


<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 - 4


<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 - 5
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 18972}]
{"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": "333-60921", "film-number": "98679559"}, "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 1998 Employee Stock Purchase 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.
---------------

                                          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             375,000                $27.875                $10,453,125                $3,083.67

Plan Participation
Interests                          (2)                     (2)                     (2)                     (2)
(1)      With respect to the 375,000  shares  issuable  under the 1998  Employee
         Stock Purchase Plan (the "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.

(2)      Pursuant  to Rule  416(c),  an  indeterminate  number of  participation
         interests in the Plan are being registered. Pursuant to Rule 457(h)(2),
         no additional  filing fee is required with respect to the participation
         interests in the Plan.
PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

         The  following  additional  documents,  which  have been  filed by Iron
Mountain   Incorporated   (the  "Company")  with  the  Securities  and  Exchange
Commission (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.

Item 4.  Description of Securities.

         Not applicable.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the shares  offered  hereby will be passed upon for the
Company by Sullivan & Worcester LLP,  Boston,  Massachusetts.  Jas. Murray Howe,
Secretary of the Company,  is of counsel to Sullivan & Worcester  LLP and is the
owner of 5,782 shares of Common Stock.

                                     II - 1
Item 6.  Indemnification of Directors and Officers.

         Section  145 of the  Delaware  General  Corporation  Law  (the  "DGCL")
provides, in effect, that any person made a party to any action by reason of the
fact that he is or was a director, officer, employee or agent of the Company may
and, in certain cases,  must be indemnified by the Company against,  in the case
of a non-derivative  action,  judgments,  fines,  amounts paid in settlement and
reasonable expenses  (including  attorney's fees) incurred by him as a result of
such action, and in the case of a derivative action, against expenses (including
attorney's  fees),  if in either  type of action he acted in good faith and in a
manner he reasonably  believed to be in or not opposed to the best  interests of
the Company.  This  indemnification  does not apply, in a derivative  action, to
matters as to which it is adjudged that the director, officer, employee or agent
is liable to the Company, unless upon court order it is determined that, despite
such  adjudication  of liability,  but in view of all the  circumstances  of the
case, he is fairly and reasonably entitled to indemnity for expenses,  and, in a
non-derivative  action,  to any  criminal  proceeding  in which such  person had
reasonable cause to believe his conduct was unlawful.

         Article  Sixth of the  Company's  Amended and Restated  Certificate  of
Incorporation  provides that the Company shall  indemnify  each person who is or
was an officer or director of the Company to the  fullest  extent  permitted  by
Section 145 of the DGCL.

         Article  Seventh of the Company's  Amended and Restated  Certificate of
Incorporation  states that no  director  of the  Company  shall be liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a  director,  except  to the  extent  that  exculpation  from  liability  is not
permitted under the DGCL as in effect when such breach occurred.

Item 7.  Exemption from Registration Claimed.

         Not Applicable.

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.

Item 9.  Undertakings.

         (a)  The undersigned registrant hereby undertakes:

                  (1) to file,  during any  period in which  offers or sales are
         being made, a post-effective amendment to this Registration Statement:

                  (i)      to  include  any   prospectus   required  by  Section
                           10(a)(3) of the Securities Act of 1933;

                  (ii)     to  reflect  in the  prospectus  any  facts or events
                           arising after the effective date of the  Registration
                           Statement   (or  the   most   recent   post-effective
                           amendment  thereof)  which,  individually  or in  the
                           aggregate,  represent  a  fundamental  change  in the
                           information set

                                     II - 2
forth in the Registration Statement.  Notwithstanding
                           the foregoing,  any increase or decrease in volume of
                           securities  offered  (if the  total  dollar  value of
                           securities  offered  would not exceed  that which was
                           registered)  and any  deviation  from the low or high
                           and of the estimated  maximum  offering  range may be
                           reflected  in the form of  prospectus  filed with the
                           Commission   pursuant  to  Rule  424(b)  if,  in  the
                           aggregate,  the changes in volume and price represent
                           no  more  than  20  percent  change  in  the  maximum
                           aggregate   offering   price   set   forth   in   the
                           "Calculation  of  Registration   Fee"  table  in  the
                           effective Registration Statement;

                  (iii)    to include any material  information  with respect to
                           the plan of distribution not previously  disclosed in
                           the Registration  Statement or any material change to
                           such information in the Registration Statement:

         provided,  however,  that  paragraphs  (a)(1)(i) and  (a)(1)(ii) do not
         apply if the  information  required to be included in a  post-effective
         amendment by those  paragraphs  is contained in periodic  reports filed
         with or  furnished  to the  Commission  by the  registrant  pursuant to
         Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that
         are incorporated by reference in the Registration Statement;

                  (2) that, for the purpose of determining  any liability  under
         the Securities Act of 1933, each such post-effective amendment shall be
         deemed to be a new  Registration  Statement  relating to the securities
         offered therein, and the offering of such securities at that time shall
         be deemed to be the initial bona fide offering thereof; and

                  (3) to remove from  registration by means of a  post-effective
         amendment any of the securities being registered which remain unsold at
         the termination of the offering;

         (b) The undersigned  registrant hereby undertakes that, for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  Act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
Registration  Statement  shall  be  deemed  to be a new  Registration  Statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof; and

         (c)  Insofar  as  indemnification  for  liabilities  arising  under the
Securities Act of 1933 may be permitted to directors,  officers and  controlling
persons of the registrant  pursuant to the foregoing  provisions,  or otherwise,
the  registrant  has been  advised  that in the  opinion of the  Securities  and
Exchange  Commission such  indemnification is against public policy as expressed
in that Act and is,  therefore,  unenforceable.  In the  event  that a claim for
indemnification  against  such  liabilities  (other  than  the  payment  by  the
registrant of expenses  incurred or paid by a director,  officer or  controlling
person of the  registrant  in the  successful  defense  of any  action,  suit or
proceeding)  is  asserted by such  director,  officer or  controlling  person in
connection with the securities being registered,  the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit  to a  court  of  appropriate  jurisdiction  the  question  whether  such
indemnification  by it is against  public policy as expressed in the  Securities
Act of 1933 and will be governed by the final adjudication of such issue.

                                     II - 3
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 - 4
/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 - 5