A 59-year-old woman with a history of lung sarcoidosis developed general edema and exertional dyspnea. An electrocardiogram showed first-degree atrioventricular block with complete right bundle branch block. Chest X-ray showed cardiomegaly. Echocardiography showed diffuse and severe hypokinesis of the left ventricle (LV) and biventricular enlargement with severe tricuspid regurgitation. Myocardial scintigraphy disclosed a perfusion defect at the ventricular septum and hypoperfusion at the posterior wall and the apex. On cardiac catheterization, pulmonary capillary wedge pressure, right ventricular, and right atrial pressures were elevated. Coronary angiograms were normal. Myocardial biopsy of the right ventricle histologically revealed epithelioid cell granuloma with infiltration of fibrous cells. The patient's symptom and LV function were improved with conventional medical therapy for heart failure. This is a rare case of cardiac sarcoidosis resulting in biventricular failure.