Exhibit 5.1 Esanu Katsky Korins & Siger, LLP 605 Third Avenue New York, New York 10158 Telephone: (212) 953-6000 Fax: (212) 953-6899 November 14, 2002 Securities and Exchange Commission 13146-02 450 Fifth Street, N.W. Washington, D.C. 20549 Re: Netsmart Technologies, Inc. Ladies and Gentlemen: We refer to the registration statement on Form S-8 (the "Registration Statement"), filed under the Securities Act of 1933, as amended (the "Act"), by Netsmart Technologies, Inc., a Delaware corporation (the "Company"), with the Securities and Exchange Commission covering the 480,000 shares of the Company's common stock, par value $.01 per share ("Common Stock"), issuable pursuant to the amendment to the Company's 2001 and 1999 Long-Term Incentive Plans (the "Plans") and the 75,000 shares of Common Stock issuable upon the exercise of an employee stock option (the "Employee Option"). We have examined the originals or photocopies or certified copies of such records of the Company evidencing approval by the board of directors and stockholders and such other documents as we have deemed relevant and necessary as a basis for the opinion hereinafter expressed. In such examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as certified copies or photocopies and the authenticity of the originals of such latter documents. Based on our examination described above, we are of the opinion that the shares of Common Stock registered pursuant to the Registration Statement are duly authorized and, when issued upon receipt of the exercise price of the options granted pursuant to the Plans or pursuant to the Employee Option, will be validly issued, fully paid and non-assessable. We hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement and to the reference to our firm under "Legal Matters" in the related Prospectus. In giving the foregoing consent, we do not hereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Securities and Exchange Commission. Very truly yours, ESANU KATSKY KORINS & SIGER, LLP