Two 31 year old patients were interned with cardiac insufficiency (functional class III). Case number one infective endocarditis with mitral valve 8 months before. Case number two had previous rheumatic disease. Both had severe mitral insufficiency and were submitted to replacement of mitral valve. Surgical findings included the presence of aneurysm mitral leaflet (posterior in case one and both in case two). The pathologic study showed mitral valve prolapse and signs of previous endocarditis in case one and rheumatic lesion in the other case.