This study was designed to prove the utility of intraoperative echocardiography in the mitral valve repair, that offers many advantages over valve replacement. We have assessed 21 consecutive patients, 12 with mitral incompetence and 9 with mitral stenosis, undergoing mitral valve surgery over a period of 6 months. Preoperative transthoracic and intraoperative transesophageal or epicardial echocardiography were performed in all patients. We have assessed, before and after repair, the valve morphology, the presence and the severity of mitral regurgitation, the pulmonary venous flow, the presence of left ventricular outflow tract obstruction. The intraoperative echocardiographic examination revealed a successful mitral repair in all patients except one in whom, for the persistence of severe mitral regurgitation after repair, valve replacement was performed. In none patient systolic anterior motion of mitral apparatus was observed. Intraoperative echocardiography seems to be a useful technique to assess the adequacy of mitral valve repair before chest closure and, in the case of failure, the need for further surgery (valve reconstruction or replacement).