Chronic degenerative mitral regurgitation (MR) is a complex problem, which requires an integrated assessment of etiology, pathophysiology, and severity to enable informed clinical decision-making. A multidisciplinary approach is required, with input from the clinician, imager, and surgeon. This review begins with a discussion of essential echocardiographic and surgical mitral valve (MV) anatomy, which dictates suitability for repair when indicated. The echocardiographic and Doppler principles, which underlie the quantitation of MR severity, are summarized in the next section, followed by a critical examination of left ventricular systolic function in this disorder. A brief discussion of the important role of imaging in the developing field of percutaneous MV repair is included. The methodical and objective noninvasive assessment of degenerative MR herein reviewed is intended to help guide management decisions for patients with this challenging valve lesion.