Cardiac involvement is commonly seen in the carcinoid syndrome (C.S.). However echocardiographic observations in this condition are still very scanty. In two patients with the C.S. and clinical signs of tricuspid insufficiency (plus mild pulmonic stenosis in one case) two-dimensional echocardiography showed: 1) right ventricular overload with normal left heart valves and chambers; 2) a peculiar aspect of the tricuspid valve, whose three leaflets were markedly thickened and retracted. The anterior leaflet was almost fixed in a semi-open position while the septal and posterior leaflets appeared as rigid structures fixed in an open position, extending from the annulus into the right ventricular cavity. In both cases only the posterior cusp of the pulmonary valve could be visualized. The afore-mentioned changes exactly reproduce the pathological features of the tricuspid valve in the carcinoid heart disease and so far, have not been observed in other conditions.