A report is presented of a patient surviving four years with a human cardiac allograft. The allograft arteries showed marked graft arteriosclerosis with intimal fibrocellular proliferation. The arteriosclerotic lesions occurring in the larger epicardial vessels were strikingly similar to spontaneous atherosclerosis. The relationship of the long-term survival to the use of a permanent transvenous pacemaker and of the development of severe vascular lesions to acute rejection and hyperlipemia are discussed.