The M-mode echocardiographic features of aortic valve structure and motion in a 45-year-old male with combined congenital subaortic diaphragm and acquired deformity of the aortic valve are described. Clinical, hemodynamic, and angiographic studies suggested calcific aortic valve disease with stenosis and insufficiency, but the additional presence of a subaortic diaphragm was not appreciated. Cardiac ultrasonography demonstrated multiple, central diastolic aortic valve cusp echoes consistent with a thickened, calcified, tricuspid aortic valve. Despite calcification of the cusps, however, enough systolic cusp excursion remained to demonstrate an early systolic, rapid movement toward closure of the right coronary cusp-a finding suggestive of fixed subvalvular obstruction. Surgery confirmed a discrete subaortic diaphragm and a tricuspid, thichened, mildly calcified aortic valve with fusion of the cusp commissures at their origins and rolling back of the cusp edges. The value of echocardiography in the evaluation of the left ventricular outflow tract and aortic valve is emphasized.