Exhibit 5.1 [Logo of Conner & Winters, P.C.] Conner & Winters, P.C. 3700 First Place Tower, 15 East Fifth Street Tulsa, Oklahoma 74103-4344 918-586-5711 October 28, 2004 ADDvantage Technologies Group, Inc. 1605 E. Iola Broken Arrow, OK 74012 Re: ADDvantage Technologies Group, Inc. Form S-3 Registration Statement Ladies and Gentlemen: We have acted as counsel to ADDvantage Technologies Group, Inc., an Oklahoma corporation (the "Company"), in connection with the preparation and filing of a registration statement on Form S-3 (the "Registration Statement") with the Securities and Exchange Commission (the "Commission") under the Securities Act of 1933, as amended (the "Act"). The Registration Statement relates to the proposed reoffer and resale from time to time by certain selling shareholders (as described in the Registration Statement) of up to 3,500,000 shares of the Company's common stock, par value $.01 per share ("Common Stock"), including up to 3,000,000 shares of Common Stock that a selling shareholder may acquire upon the exercise of options granted by third parties. The Common Stock will be sold or delivered from time to time as set forth in the Registration Statement, the applicable prospectus contained therein (the "Prospectus") and any supplements to the Prospectus. In reaching the conclusions expressed in this opinion, we have (a) examined the Registration Statement and such corporate records, certificates of officers, other documents, and questions of law as we have considered necessary or appropriate, (b) relied upon the accuracy of facts and information set forth in all such documents, and (c) assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as copies, and the authenticity of the originals from which all such copies were made. Based on the foregoing and subject to the qualifications and limitations stated herein, we are of the opinion that the 3,500,000 shares covered by the Registration Statement are validly issued, fully paid, and non-assessable shares of Common Stock. Our opinions expressed above are limited to the laws of the State of Oklahoma and the federal law of the United States of America, and we do not express any opinion herein concerning the laws of any other jurisdiction. We hereby consent to the reference to our firm under the heading "Legal Opinion" in the Prospectus and to the filing of this opinion as Exhibit 5.1 to the Registration Statement. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission promulgated thereunder. Very truly yours, CONNER & WINTERS, P.C. /s/ Conner & Winters