Chronic severe mitral regurgitation is a surgically correctable disorder. Advances in cardiac surgery (including mitral valve repair and less invasive operations), a low postoperative complication rate, and improved long-term prognosis have reduced the threshold for surgical referral. Choosing the optimal timing for surgery remains the cardinal problem. Clinical and diagnostic imaging information is essential to the detection of occult myocardial decompensation, for which surgical correction should be sought. Surgery is not generally recommended in asymptomatic patients without signs of progressive disease. The final decision regarding timing of surgery should be made based on all the clinical data, the patient's choice, and the available surgical expertise. The use of medical therapy to delay the time to surgery is not supported by large trials; however, small short-term studies of chronic vasodilator therapy show favorable hemodynamic effects.