AbstractRecords from 18 subjects with angiographic idiopathic mitral valve prolapse, 28 subjects with merely exaggerated posterior mitral leaflet systolic bulging, and 100 subjects with normal hemodynamic and angiographic findings were compared with regard to age, sex, height, weight, ponderal index (height/3 weight), auscultatory and echocardiographic abnormalities. Chest x‐ray films available for subjects with mitral valve prolapse were reviewed.The ponderal index of subjects with mitral valve prolapse (13.1 ± 0.8) differed from that of subjects with merely exaggerated posterior mitral leaflet systolic bulging (12.6 ± 0.7) (P < 0.02) and from that of subjects without angiographic abnormality (12.3 ± 0.8) (P < 0.001). The three groups differed in ponderal index when equated statistically for age, height, weight, and sex (P < 0.001). Among mitral valve prolapse patients, an asthenic habitus occurred independent of the presence of thoracic skeletal abnormalities.