Backgrounds: The benefits of adjunctive mitral valve (MV) repair at the time of coronary artery bypass graft surgery (CABG) for patients with ischemic mitral regurgitaiton (MR) remains unclear. We sought to test the hypothesis that MV repair with CABG is superior to CABG alone in improving MR without an increase in operative or long-term mortality. Methods: From 1997 to 2003, 107 consecutive patients with moderate or severe ischemic functional MR determined by preoperative echocardiography underwent CABG with concomitant MV repair (repair group, n=50) or CABG only (CABG group, n=57). Degree of MR was graded as none, mild, moderate, or severe by proximal isovelocity surface area method, and improvement in MR was defined as decrease of MR in severity ���1 grade on follow-up echocardiography. Results: The operative morality of repair group was significantly higher than CABG group, but 5-year actuarial survival rate was similar between two groups. On multivariate analysis, old age and Af were independent predictors of operative morality (p<0.05). Among patients with severe MR, ischemic MR was improved in all patients of repair group and 67% of patients in CABG group (p<0.001), while improvement rates in patients with moderate MR were similar between two groups (69% vs.67%, p=NS). Conclusions: Although MV repair appears to be more effective at reducing ischemic functional MR, CABG alone might be a preferable treatment option for patients with high operative risk or moderate MR.