Exhibit 5.1

Christian E. Plaza

T: (703) 456-8006

cplaza@cooley.com

December 5, 2007

Gladstone Commercial Corporation
1521 Westbranch Drive, Suite 200
McLean, Virginia 22102

Ladies and Gentlemen:

We have acted as counsel to Gladstone Commercial Corporation, a Maryland corporation (the “Company”), in connection with the Registration Statement on Form S-3 (the “Registration Statement”) to be filed by the Company under the Securities Act of 1933, as amended (the “Securities Act”). The Company has provided us with a prospectus (the “Prospectus”), which forms part of the Registration Statement. The Prospectus provides that it will be supplemented in the future by one or more prospectus supplements (each, a “Prospectus Supplement”). The Registration Statement, including the Prospectus as supplemented from time to time by one or more Prospectus Supplements, will provide for the registration by the Company of:

	•		shares of common stock, par value $0.001 per share, of the Company (the “Common Stock”); and
	•		shares of preferred stock, par value $0.001 per share, of the Company (the “Preferred Stock”);

The Common Stock and the Preferred Stock are collectively referred to herein as the “Securities.” The Securities are being registered for offering and sale from time to time pursuant to Rule 415 under the Securities Act. The aggregate public offering price of the Securities being registered is $300 million.

In connection with this opinion, we have examined and relied upon originals, or copies certified to our satisfaction, of such records, documents, certificates, opinions, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. As to certain factual matters, we have relied upon certificates of the officers of the Company and have not sought independently to verify such matters.

ONE FREEDOM SQUARE RESTON TOWN CENTER 11951 FREEDOM DRIVE RESTON VA 20190-5656 T: (703) 456-8000 F: (703) 456-8100 WWW.COOLEY.COM

Gladstone Commercial Corporation
December 5, 2007
Page Two

In rendering this opinion, we have assumed the genuineness and authenticity of all signatures on original documents; the authenticity of all documents submitted to us as originals; the conformity to originals of all documents submitted to us as copies; the accuracy, completeness and authenticity of certificates of public officials; and the due authorization, execution and delivery of all documents where authorization, execution and delivery are prerequisites to the effectiveness of such documents. With respect to our opinion as to the Common Stock, we have assumed that, at the time of issuance and sale, a sufficient number of shares of Common Stock is authorized and available for issuance and that the consideration for the issuance and sale of such shares of Common Stock (or Preferred Stock convertible into Common Stock) is not less than the par value of the Common Stock. With respect to our opinion as to the Preferred Stock, we have assumed that, at the time of issuance and sale, a sufficient number of shares of Preferred Stock is authorized, designated and available for issuance and that the consideration for the issuance and sale of such shares of Preferred Stock is not less than the par value of the Preferred Stock.  

Our opinion herein is expressed solely with respect to the federal laws of the United States and the laws of the State of Maryland. We express no opinion as to whether the laws of any jurisdiction are applicable to the subject matter hereof. We are not rendering any opinion as to compliance with any antifraud law, rule or regulation relating to securities, or to the sale or issuance thereof.

On the basis of the foregoing and in reliance thereon, and subject to the qualifications herein stated, we are of the opinion that:

1. With respect to the Common Stock offered under the Registration Statement, provided that (i) the Registration Statement and any required post-effective amendment thereto have all become effective under the Securities Act and the Prospectus and any and all Prospectus Supplement(s) required by applicable laws have been delivered and filed as required by such laws; (ii) the issuance of such Common Stock has been duly authorized by all necessary corporate action on the part of the Company; (iii) the issuance and sale of such Common Stock do not violate any applicable law, are in conformity with the Company’s then operative articles of incorporation (the “Articles of Incorporation”) and bylaws (“Bylaws”), do not result in a default under or breach of any agreement or instrument binding upon the Company and comply with any requirement imposed by any court or governmental body having jurisdiction over the Company; and (iv) the certificates for such Common Stock have been duly executed by the Company, countersigned by the transfer agent therefor and duly delivered to the purchasers thereof against payment therefor (or in the case of uncertificated securities, the Company has delivered, in accordance with Section 2-210 of the Maryland General Corporation Law (“MGCL”), a written statement of the information required on certificates by Section 2-211 of MGCL), then the shares of such Common Stock, when issued and sold in accordance with a duly authorized, executed and delivered purchase, underwriting or similar agreement or upon conversion of any convertible Preferred Stock will be duly authorized, validly issued, fully paid and nonassessable.

ONE FREEDOM SQUARE RESTON TOWN CENTER 11951 FREEDOM DRIVE RESTON VA 20190-5656 T: (703) 456-8000 F: (703) 456-8100 WWW.COOLEY.COM