<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE AUDITED
CONSOLIDATED BALANCE SHEETS AT DECEMBER 31, 1997 AND 1998, AND THE AUDITED
CONSOLIDATED STATEMENTS OF OPERATIONS FOR THE YEARS THEN ENDED AND IS QUALIFIED
IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. ON JUNE 30, 1998, THE
COMPANY'S BOARD OF DIRECTORS AUTHORIZED AND APPROVED A THREE-FOR-TWO STOCK SPLIT
EFFECTED IN THE FORM OF A DIVIDEND ON THE COMPANY'S COMMON STOCK. SUCH
ADDITIONAL SHARES OF COMMON STOCK WERE ISSUED ON JULY 31, 1998 TO ALL
STOCKHOLDERS OF RECORD AS OF THE CLOSE OF BUSINESS ON JULY 17, 1998. ALL ISSUED
AND OUTSTANDING SHARE AND PER SHARE AMOUNTS IN THE ACCOMPANYING FINANCIAL
STATEMENTS AND NOTES THERETO HAVE BEEN RESTATED TO REFLECT THE STOCK SPLIT.
PREVIOUS FDS HAVE NOT BEEN RESTATED TO REFLECT THE STOCK SPLIT.
</LEGEND>
<CIK>          0001004317
<NAME>         IRON MOUNTAIN INCORPORATED
<MULTIPLIER>   1,000
<CURRENCY>     U.S. DOLLARS
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   YEAR                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1998
<PERIOD-START>                             JAN-01-1997             JAN-01-1998
<PERIOD-END>                               DEC-31-1997             DEC-31-1998
<EXCHANGE-RATE>                                  1.000                   1.000
<CASH>                                          24,510                   1,715
<SECURITIES>                                         0                       0
<RECEIVABLES>                                   42,474                  78,881
<ALLOWANCES>                                   (1,929)                 (3,316)
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                81,927                 143,937
<PP&E>                                         245,174                 354,101
<DEPRECIATION>                                (61,276)                (87,358)
<TOTAL-ASSETS>                                 636,786                 967,385
<CURRENT-LIABILITIES>                           55,753                 143,472
<BONDS>                                        425,018                 456,178
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                           202                     294
<OTHER-SE>                                     137,531                 338,588
<TOTAL-LIABILITY-AND-EQUITY>                   636,786                 967,385
<SALES>                                        208,765                 423,512
<TOTAL-REVENUES>                               208,765                 423,512
<CGS>                                          106,879                 220,980
<TOTAL-COSTS>                                  185,654                 375,157
<OTHER-EXPENSES>                                     0                 (1,384)
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                              27,712                  45,756
<INCOME-PRETAX>                                (4,601)                   3,983
<INCOME-TAX>                                      (80)                   6,949
<INCOME-CONTINUING>                            (4,521)                 (2,966)
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                   (4,521)                 (2,966)
<EPS-PRIMARY>                                   (0.26)                  (0.11)
<EPS-DILUTED>                                   (0.26)                  (0.11)
        

</TABLE>