OBJECTIVE To study the incidence of ischemic mitral regurgitation (MR) and the mortality. METHODS One-hundred-five cases of acute myocardial infarction (AMI) with MR were reviewed. Patients were divided in two groups: group A-59 (56.2%) necropsied patients without previous surgical procedures to correlate clinical pictures with the aim to determine the cause of death; group B-46 (43.8%) patients were submitted to surgical treatment. This group was subdivided in mild, moderate and severe forms of MR, and studied comparatively the type of surgical treatment and its evolution. RESULTS Group A-23 (39%) patients with mild forms and predominant ischemic heart disease, responsible for death; 18 (30.5%) patients without previous diagnosis, masked by myocardial failure and 18 (30.5%) with severe MR and coronary heart disease; group B-14 (30.4%) patients died at the immediate post-operatory period. Higher mortality associated to ejection fraction (EF) below 35% (47.6%; p = 0.022), severe MR (41.7%; p = 0.044) and cardiogenic shock (52.9%; p = 0.14). In 41 (89.1%), the mitral valve repair was combined to coronary artery bypass grafting operation (CABG), in 4 (8.7%) this last procedure was made without mitral repair and in the remaining patients the surgery was limited to the valve. Mitral valvuloplasty was performed in 23 (50%) patients with 3 (13%) deaths, and in 19 (42.3%) the mitral valve was replaced with 9 (47.4%) deaths. CONCLUSIONS The prognosis is related to the grade of EF and to the severity of MR. In mild to moderate forms, the surgical indication is due to the associated coronary heart disease and the valvuloplasty is preferred, in this instance. In severe forms, surgical intervention must be performed as soon as possible, before cardiogenic shock appears.