The optimal management of moderate (grade 2-3+) ischemic mitral regurgitation (MR) in patients undergoing coronary artery bypass grafting (CABG) remains controversial. While CABG alone can reverse regurgitation in some patients with moderate MR, adjunctive mitral repair may be necessary in others. We performed low-dose dobutamine stress echocardiography (DSE) in 60 patients with moderate MR who were about to undergo CABG. Group I, 25 patients who demonstrated reduction in MR during DSE, had CABG alone. Group II, 35 patients in whom MR was unchanged during DSE, had mitral valve repair as well as CABG. MR was reduced postoperatively in both groups (P < 0.0001). Postoperative ejection fraction in Group I (12.2%) improved more than that in Group II (9.3%) (P < 0.01). We conclude that CABG alone may be sufficient to correct moderate MR when MR is reduced during DSE.