One hundred forty-five patients (74 women, 71 men), aged 60 years and older, with echocardiographically documented mitral valve prolapse were studied. One hundred sixteen patients had precordial systolic murmurs, 20 of whom were suspected of having mitral valve prolapse before the echocardiographic study. Infective endocarditis occurred in 7 patients, cerebral ischemic events in 13 and spontaneous rupture of chordae tendineae in 33. Four other patients had ruptured chordae tendineae associated with infective endocarditis. Congestive heart failure was present in 35 patients, 11 of whom had undergone mitral valve surgery.