We present here an unusual case of massive annular calcification leading to severe mitral regurgitation in a patient with chronic renal failure. The patient was referred for dyspnea, which was attributed to severe mitral regurgitation. Echocardiographic examination revealed extensive mitral annular and valvular calcification extending into the left atrial wall. Despite her massive annular calcification, she experienced neither embolism nor endocarditis before. Because of severe mitral insufficiency, surgery was performed. The surgery, which consisted of replacing the mitral valve with bioprosthesis and removing calcific deposits, was uneventful.