A case of carcinoid heart disease with prominent left heart involvement in addition to the usual right heart lesion is described. The foramen ovale was closed, and no communication could be demonstrated between the right and left sides of the heart. The clinical data lead to the diagnosis of tricuspid insufficiency, and also pulmonary valvular stenosis was suspected. Left ventricular failure accompanied by electrocardiographic and x-ray evidence of left ventricular involvement occurred early in the course of the illness and was thought to be related to pre-existing hypertensive heart disease rather than to the endocardial lesion of the left ventricle.