<SUBMISSION>
<ACCESSION-NUMBER>0001020569-07-000001
<TYPE>5
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20061231
<FILING-DATE>20070214
<DATE-OF-FILING-DATE-CHANGE>20070214
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>REESE C RICHARD
<CIK>0001032365
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>5
<ACT>34
<FILE-NUMBER>001-13045
<FILM-NUMBER>07614622
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>6173576966
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O IRON MOUNTAIN INC
<STREET2>745 ATLANTIC AVE 10TH FLR
<CITY>BOSTON
<STATE>MA
<ZIP>02111
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>IRON MOUNTAIN INC
<CIK>0001020569
<ASSIGNED-SIC>4220
<IRS-NUMBER>232588479
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>745 ATLANTIC AVENUE
<CITY>BOSTON
<STATE>MA
<ZIP>02111
<PHONE>6175354766
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>745 ATLANTIC AVENUE
<CITY>BOSTON
<STATE>MA
<ZIP>02111
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>IRON MOUNTAIN INC/PA
<DATE-CHANGED>20000201
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>PIERCE LEAHY CORP
<DATE-CHANGED>19960807
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2006-12-31</periodOfReport>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0001020569</issuerCik>
        <issuerName>IRON MOUNTAIN INC</issuerName>
        <issuerTradingSymbol>IRM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001032365</rptOwnerCik>
            <rptOwnerName>REESE C RICHARD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 BELVEDERE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>APT. 9F</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02199</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value, $01.per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1052097</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value, $01.per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1222086</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Shares held in family owned LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value, $01.per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2950588</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By contract</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Common Stock of Iron Mountain Incorporated split, December 29, 2006 3-for-2 to record holders as of December 18, 2006, resulting in the reporting person's acquisition of 350,699 shares of Common Stock. Mr. Reese's directly owned shares include 966,552 shares subject to a zero collar arrangement with a third party to which Mr. Reese wrote covered call options and purchased put options that expire or are exercisable in July, August and September 2008, respectively.</footnote>
        <footnote id="F2">The split on December 29, 2006 3-for-2 to record holders as of December 18, 2006, resulted in the reporting person's indirect ownership and additional 407,362 shares of Common Stock. Mr. Reese's wife and a trust for the benefit of Mr. Reese's children own all of the interests in the Reese Family 2005 LLC (&quot;LLC&quot;). Mr. Reese is the investment manager of the Reese Family 2005 LLC and therefore has control over the sale or distribution of any shares held by the LLC,  the timing of such sales or distributions, and the use of the proceeds of any sale or distributions. Mr. Reese disclaims beneficial ownership of all securities held by the Reese Family 2005 LLC and this report should not be deemed an admission that the reporting person is beneficial owner of such securities for purposes of Section 16 of the Exchange Act of 1934, as amended, or for any purpose. The 980 shares gifted by Mr. Reese to his children on December 15, 2005 were subsequently transferred to the LLC on 2/9/06.</footnote>
        <footnote id="F3">The Common Stock of Iron Mountain Incorporated split, December 29, 2006 3-for-2 to record holders as of December 18, 2006, resulting in the reporting person's indirect ownership and additional 983,529 shares of Common Stock. Pursuant to a deferred compensation arrangement relating to Mr. Reese's former services as President of Schooner Capital Corporation (&quot;Schooner&quot;), upon the earlier to occur of (i) sale or exchange by Schooner Capital Trust of substantially all of the shares of Iron Mountain Incorporated Common Stock, par value $.01 per share (&quot;Common Stock&quot;) held by Schooner Capital Trust and (ii) the cessation of Mr. Reese's employment with Iron Mountain Incorporated, Schooner Capital Trust is required to transfer such shares of Common Stock to Mr. Reese or cash in an amount equal to then current fair market value of such shares of Common Stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>C. Richard Reese</signatureName>
        <signatureDate>2007-02-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
