Functional ischemic mitral regurgitation (MR) has been reported to occur in up to 40% of patients after myocardial infarction, and the prevalence of functional MR is likely to increase with an aging population and improved survival rates for myocardial infarction. The presence of functional MR is associated with an increased incidence of heart failure and death, and patients with significant functional MR incur about a two-fold increase in the risk of mortality and about a four-fold increase in the risk of heart failure. Functional MR is caused by adverse left ventricular remodeling after myocardial injury with enlargement of the left ventricle (LV), apical and lateral displacement of papillary muscles, leaflet tethering and reduced closing forces. The leaflets are normal in secondary functional MR and the treatment is considerably different between functional and primary MR. Surgery is the only definitive therapy for primary severe MR and primary MR can usually be cured by surgical valve repair. However, surgical indications are unclear in severe functional MR, because outcomes after surgery for functional MR remain suboptimum. Operative mortality, long-term mortality and heart failure rates are still high in patients with severe functional MR despite surgical improvements. According to the current guidelines, mitral valve surgery may be considered only for severely symptomatic patients with severe secondary functional MR who have persistent symptoms despite optimal medical therapy for heart failure.