Degenerative mitral valve (MV) disease refers to a collection of ill-defined pathologies of the MV which manifest as mitral regurgitation (MR). Untreated MR may progress to heart failure and death. Recent advances in the surgical technique of MV repair have improved long-term surgical results to the extent that early surgery is advocated in most patients with severe MR even when asymptomatic to restore normal functional capacity and life expectancy. This article reviews the pathophysiology, evaluation, treatment, and results of surgical intervention for degenerative MR.