EXHIBIT 5.1 AHLERS, COONEY, DORWEILER, HAYNIE, SMITH & ALLBEE, P.C. ATTORNEYS AT LAW KENNETH H. HAYNIE WILLIAM J. NOTH STEVEN L. SERCK OF COUNSEL JOHN F. MCKINNEY, JR. DAVID SWINTON STEVEN M. NADEL PAUL F. AHLERS 100 COURT AVENUE, SUITE 600 RICHARD G. SANTI LINDA L. KNIEP ELIZABETH A. GROB H. RICHARD SMITH DES MOINES, IOWA 50309-2231 EDGAR H. BITTLE JOHN D. HINTZE JENNIFER A. CLENDENIN ROBERT G. ALLBEE RONALD L. SUTPHIN PETER PASHLER PATRICIA A. WESTEMEYER DOUGLAS R. SMITH LANCE A. COPPOCK IVAN T. WEBBER NATHAN J. OVERBERG PHILIP J. DORWEILER, Retired http://www.ahlerslaw.com DAVID H. LUGINBILL JANE B. MCALLISTER DANIELLE J. LATHAM JAMES EVANS COONEY MARK W. BEERMAN JAMES C. HANKS JAMES R. WAINWRIGHT (1917-1998) TELEPHONE 515-243-7611 EDWARD W. REMSBURG R. MARK CORY J. ERIC BOEHLERT TELECOPIER 515-243-2149 RANDALL H. STEFANI SERGE H. GARRISON GORDON D. GRETA ELIZABETH GREGG KENNEDY RONALD L. PEELER MARK W. JOHNSON WADE R. HAUSER III ANDREW J. BRACKEN April 23, 2001 Mahaska Investment Company 222 First Avenue East Oskaloosa, Iowa 52577 Re: Mahaska Investment Company Registration Statement on Form S-8 1998 Stock Incentive Plan ------------------------- Gentlemen: We are acting as counsel to Mahaska Investment Company (the "Corporation") in connection with the filing with the Securities and Exchange Commission of a Registration Statement on Form S-8 (the "Registration Statement") relating to up to 550,000 shares of the Corporation's common stock, par value $5.00 per share (the "Common Stock"). The Common Stock is distributable under the Corporation's 1998 Stock Incentive Plan (the "Plan"). The opinion set forth below relates only to the Common Stock covered by the Registration Statement. In connection with our opinion, we have examined originals, or copies, certified or otherwise identified to our satisfaction, of the Registration Statement, the Articles of Incorporation, as amended, and the Bylaws of the Corporation, as well as such other corporate records, documents and other papers as we deemed necessary to examine for purposes of this opinion. In making such examination, we have assumed as true, without independent review or verification, facts certified to us by certain executive officers of the Corporation and by public officials. Mahaska Investment Company April 23, 2001 Page 2 Based on the foregoing, we are of the opinion that the 550,000 shares of Common Stock when issued by the Corporation in accordance with the Plan will be duly authorized, validly issued, fully paid and nonassessable shares of Common Stock. The opinion expressed herein is limited to the laws and judicial practices of the State of Iowa currently in effect. We hereby consent to the use of this opinion in connection with the Registration Statement and to references to our firm therein. Sincerely yours, AHLERS, COONEY, DORWEILER, HAYNIE, SMITH & ALLBEE, P.C. John D. Hintze