Senior Housing Properties Trust Announces Underwriters' Exercise of Over-Allotment Option

Senior Housing Properties Trust (NYSE: SNH) today announced that the underwriters of its recent equity offering have exercised their over-allotment option in full to purchase 2,550,000 additional common shares of beneficial interest. The sale price of these shares will be $21.09 per share, less underwriting discounts and commissions. The sale of the additional shares and the sale of the original public offering of 17,000,000 common shares are expected to close on Friday, June 6, 2008.

The joint book-running managers for this offering were UBS Investment Bank, Merrill Lynch & Co. and Morgan Stanley. The co-lead managers for this offering were Citi and RBC Capital Markets. The co-managers for this offering were Robert W. Baird, Janney Montgomery Scott LLC, Keefe Bruyette & Woods, Morgan Keegan & Company, Inc., Oppenheimer & Co., and Stifel Nicolaus.

This press release shall not constitute an offer to sell, nor a solicitation of an offer to buy, shares, nor shall there be any sale of these securities in any state or jurisdiction in which the offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such state or jurisdiction. Copies of the prospectus supplement and related prospectus may be obtained from the offices of UBS Investment Bank, Attention: Prospectus Department, at 299 Park Avenue, New York, NY, 10171 (telephone: 212-821-3000), from the offices of Merrill Lynch & Co., 4 World Financial Center, New York, New York 10080 (telephone: 212-449-1000) from the offices of Morgan Stanley, 180 Varick St., 2nd Floor, New York, New York, Attention: Prospectus Department or by email at prospectus@morganstanley.com, or by contacting any of the other managing underwriters.

A Maryland Real Estate Investment Trust with transferable shares of beneficial interest listed on the New York Stock Exchange.

No shareholder, Trustee or officer is personally liable for any act or obligation of the Trust.