As filed with the Securities and Exchange Commission on November 18, 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 Executive Deferred Compensation Plan
                            (Full title 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
                                ----------------






<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 Obligation(1)     Offering Price(1)       Registration Fee
    ----------------           ----------        -----------------------     -----------------       ----------------
<S>                          <C>                         <C>                    <C>                    <C>

Deferred
Compensation                  $20,000,000                 100%                   $20,000,000             $5,560.00
Obligations(2)                                  
<FN>
(1)      With respect to the Deferred Compensation  Obligations registered under
         the Iron Mountain  Incorporated  Executive Deferred  Compensation Plan,
         the proposed  maximum  offering  price per  obligation 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.

(2)      The Deferred Compensation Obligations are unsecured obligations of Iron
         Mountain  Incorporated  to pay deferred  compensation  in the future in
         accordance with the terms of the Iron Mountain  Incorporated  Executive
         Deferred Compensation Plan.
</FN>
</TABLE>



<PAGE>



PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3.  Incorporation of Documents by Reference.

         The  following  documents,  which  have  been  filed  by Iron  Mountain
Incorporated  (the "Company") with the Securities and Exchange  Commission,  are
incorporated by reference in and made a part of this Registration  Statement, as
of their respective dates:

         o        The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended September 30, 1998;

         o        The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended June 30, 1998;

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

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

         o        The Company's  Current Report on Form 8-K dated  September 18,
                  1998;

         o        The Company's  Current  Report on Form 8-K dated July 10, 1998
                  (amended August 7, 1998);

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

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

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

         o        The Company's  Current  Report on Form 8-K dated  February 18,
                  1998 (amended April 7, 1998);

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

         o        The  description of the common stock of the Company  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,
subsequent  to the date hereof and prior to the  termination  of the offering of
securities registered pursuant to this Registration  Statement,  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.

         Under the Iron Mountain  Incorporated  Executive Deferred  Compensation
Plan (the "Plan"),  the Company will provide eligible  employees the opportunity
to defer the payment to them by the

                                     II - 1

<PAGE>

Company or any subsidiary of between five and fifty percent of their base salary
and between five and one hundred percent of any incentive  compensation  bonuses
by making a written election with the Plan's  administrator.  The obligations of
the  Company  under  the Plan  (the  "Obligations")  will be  unsecured  general
obligations of the Company to pay the deferred  compensation,  with earnings, in
the future in accordance  with the terms of the Plan, and the  Obligations  will
rank equally with other unsecured and unsubordinated indebtedness of the Company
from time to time outstanding.

         Each  participating  employee  (each a  "Participant")  will  elect the
amount of compensation to be deferred in accordance with the Plan.  Participants
will  choose  hypothetical  investment  options  from the range  provided by the
Company. A hypothetical investment in the Company's stock will not be an option.
Each  Obligation  will  be  payable  by  the  Company  upon  the   Participant's
retirement,  death, disability or termination of employment or such earlier date
selected  by each  Participant  in  accordance  with the terms of the Plan.  The
Participant may elect to receive benefits in either a single lump sum in cash or
substantially equal annual cash installments over a period of either five or ten
years.

         No benefit,  payment,  sum or other interest under this Plan is subject
in any manner to anticipation,  alienation, sale, transfer,  assignment, pledge,
hypothecation, encumbrance or charge.

         The Plan  constitutes a promise by the Company to make benefit payments
to Participants and  beneficiaries in the future in accordance with the terms of
the Plan.  Any  amounts  payable  under the Plan will be paid out of the general
assets of the Company and each  Participant and beneficiary will be deemed to be
a general unsecured creditor of the Company.

         The Company will  establish a "grantor"  trust to meet its  obligations
under the Plan,  the  assets of which  will be  treated,  for all  purposes,  as
general,  unrestricted assets of the Company. In all events, it is the intent of
the Company that the Plan be treated as unfunded for tax and ERISA purposes.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the Obligations  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
15,000 shares of common stock of the Company.

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.

                                     II - 2

<PAGE>

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  (Sloan  Vaults,  Inc.  and
                  Affiliate, Midwest Records Management and InterMation, Inc.)*

         23.3     Consent  of  Carbis   Walker  &   Associates,   LLP  (National
                  Underground Storage, Inc.)*

         23.4     Consent of Arthur Andersen LLP (Iron Mountain Incorporated)*

         23.5     Consent  of  Ernst & Young  LLP  (Arcus  Technology  Services,
                  Inc.)*

         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 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

                                     II - 3


<PAGE>



         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 - 4


<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 18th
day of November, 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 18th day of November, 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 - 5


<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




           Clarke H. Bailey              Director



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







                                     II - 6
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 21536}]
{"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": "333-67499", "film-number": "98754850"}, "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 November 18, 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 Executive Deferred Compensation Plan
                            (Full title 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
                                ----------------
---------------

                                            CALCULATION OF REGISTRATION FEE

                                                                                  Proposed
                                                        Proposed                  Maximum
   Title of Securities        Amount to be          Maximum Offering             Aggregate               Amount of
    to be Registered           Registered        Price Per Obligation(1)     Offering Price(1)       Registration Fee
    ----------------           ----------        -----------------------     -----------------       ----------------
Deferred
Compensation                  $20,000,000                 100%                   $20,000,000             $5,560.00
Obligations(2)
(1)      With respect to the Deferred Compensation  Obligations registered under
         the Iron Mountain  Incorporated  Executive Deferred  Compensation Plan,
         the proposed  maximum  offering  price per  obligation 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.

(2)      The Deferred Compensation Obligations are unsecured obligations of Iron
         Mountain  Incorporated  to pay deferred  compensation  in the future in
         accordance with the terms of the Iron Mountain  Incorporated  Executive
         Deferred Compensation Plan.
PART II - INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

         The  following  documents,  which  have  been  filed  by Iron  Mountain
Incorporated  (the "Company") with the Securities and Exchange  Commission,  are
incorporated by reference in and made a part of this Registration  Statement, as
of their respective dates:

         o        The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended September 30, 1998;

         o        The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended June 30, 1998;

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

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

         o        The Company's  Current Report on Form 8-K dated  September 18,
                  1998;

         o        The Company's  Current  Report on Form 8-K dated July 10, 1998
                  (amended August 7, 1998);

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

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

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

         o        The Company's  Current  Report on Form 8-K dated  February 18,
                  1998 (amended April 7, 1998);

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

         o        The  description of the common stock of the Company  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,
subsequent  to the date hereof and prior to the  termination  of the offering of
securities registered pursuant to this Registration  Statement,  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.

         Under the Iron Mountain  Incorporated  Executive Deferred  Compensation
Plan (the "Plan"),  the Company will provide eligible  employees the opportunity
to defer the payment to them by the

                                     II - 1
Company or any subsidiary of between five and fifty percent of their base salary
and between five and one hundred percent of any incentive  compensation  bonuses
by making a written election with the Plan's  administrator.  The obligations of
the  Company  under  the Plan  (the  "Obligations")  will be  unsecured  general
obligations of the Company to pay the deferred  compensation,  with earnings, in
the future in accordance  with the terms of the Plan, and the  Obligations  will
rank equally with other unsecured and unsubordinated indebtedness of the Company
from time to time outstanding.

         Each  participating  employee  (each a  "Participant")  will  elect the
amount of compensation to be deferred in accordance with the Plan.  Participants
will  choose  hypothetical  investment  options  from the range  provided by the
Company. A hypothetical investment in the Company's stock will not be an option.
Each  Obligation  will  be  payable  by  the  Company  upon  the   Participant's
retirement,  death, disability or termination of employment or such earlier date
selected  by each  Participant  in  accordance  with the terms of the Plan.  The
Participant may elect to receive benefits in either a single lump sum in cash or
substantially equal annual cash installments over a period of either five or ten
years.

         No benefit,  payment,  sum or other interest under this Plan is subject
in any manner to anticipation,  alienation, sale, transfer,  assignment, pledge,
hypothecation, encumbrance or charge.

         The Plan  constitutes a promise by the Company to make benefit payments
to Participants and  beneficiaries in the future in accordance with the terms of
the Plan.  Any  amounts  payable  under the Plan will be paid out of the general
assets of the Company and each  Participant and beneficiary will be deemed to be
a general unsecured creditor of the Company.

         The Company will  establish a "grantor"  trust to meet its  obligations
under the Plan,  the  assets of which  will be  treated,  for all  purposes,  as
general,  unrestricted assets of the Company. In all events, it is the intent of
the Company that the Plan be treated as unfunded for tax and ERISA purposes.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the Obligations  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
15,000 shares of common stock of the Company.

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.

                                     II - 2
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  (Sloan  Vaults,  Inc.  and
                  Affiliate, Midwest Records Management and InterMation, Inc.)*

         23.3     Consent  of  Carbis   Walker  &   Associates,   LLP  (National
                  Underground Storage, Inc.)*

         23.4     Consent of Arthur Andersen LLP (Iron Mountain Incorporated)*

         23.5     Consent  of  Ernst & Young  LLP  (Arcus  Technology  Services,
                  Inc.)*

         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 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

                                     II - 3
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 - 4
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 18th
day of November, 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 18th day of November, 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 - 5
/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

           Clarke H. Bailey              Director

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

                                     II - 6