A 59-year-old male with congestive heart failure caused by impaired left ventricular function after coronary artery bypass grafting (CABG) was referred to our hospital, and massive ischemic mitral regurgitation was detected by echocardiography. This patient underwent on-pump beating-heart mitral valve repair without aortic cross-clamp successfully through right thoracotomy. Postoperative echocardiography revealed no mitral regurgitation. The patient recovered uneventfully and was discharged on the 17th postoperative day. At 6th month after the operation, he is well without mitral regurgitation.