Washington Real Estate Investment Trust (WRE)

(Former name, former address and former fiscal year, if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding twelve (12) months (or such shorter period that the Registrant was required to file such report) and (2) has been subject to such filing requirements for the past ninety (90) days.    YES  x    NO  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definition of “large accelerated filer,” “accelerated filer” or “smaller reporting company” in Rule 12b-2 of the Exchange Act). (Check One):

Large Accelerated Filer  x    Accelerated Filer  ¨    Non-Accelerated Filer  ¨    Smaller Reporting Company  ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    YES  ¨    NO  x

Number of shares outstanding of common stock, as of November 6, 2008: 52,389,115

Table of Contents

WASHINGTON REAL ESTATE INVESTMENT TRUST

INDEX