Of 20 patients with fatal osteogenic sarcoma who underwent postmortem examination, four had metastases to the heart. One had recurrent ventricular tachycardia, and one had anatomic evidence of aortic regurgitation due to massive periaortic neoplastic infiltration that prevented coaptation of the aortic cusps during ventricular diastole, one had massive invasion of the peri-superior vena caval syndrome, and one had neoplastic obstruction of the inferior vena cava as it entered the thorax. Among patients with either primary or secondary neoplasms to the heart, osteogenic sarcoma is unique because the metastases contain bone and, therefore, may be radiographically visible; they are usually large and often intracavitary.