Iron Mountain Incorporated Declares Three-for-Two Stock Split

May 27, 2004

Boston, MA - Iron Mountain Incorporated (NYSE: IRM), the leader in records and information management services, announced that the Company's Board of Directors, at a meeting held earlier today, authorized and approved a three-for-two stock split effected in the form of a dividend on the Company's Common Stock, par value $.01 per share (the "Common Stock"). Shares of Common Stock will be issued on June 30, 2004, to all stockholders of record as of the close of business on June 15, 2004. Any fractional shares resulting from the dividend will be paid in cash. The stock split will increase Iron Mountain's total shares outstanding from approximately 86 million to approximately 129 million.

Richard Reese, Chairman and CEO, stated, "In making its decision to split the stock, the Board of Directors considered the Company's solid financial performance together with the continuing appreciation of its stock price. This action reflects the Board's continued confidence in the long-term performance of the business. We also believe that the stock split will broaden the marketability and distribution of our stock."

Contact:

Stephen Golden
Investor Relations
Iron Mountain
Phone: 617-535-4799
sgolden@ironmountain.com