Primary malignant fibrous histiocytoma located in the right side of the heart is extremely rare. We reported a case with literal reviews. A 71-year-old woman was admitted of faintness due to hypotension and marked edema of her lower extremity. With no time she was deteriorated into cardiogenic shock. Echocardiography demonstrated a tumor like mass which occupied her whole right ventricular cavity. Emergency tumor resection was carried out because of her status. Histological and immunohistochemical studies revealed the tumor was malignant fibrous histiocytoma. She died of pulmonary failure on nineteenth day after surgery.