The major cause of late death in cardiac transplant recipients is cardiac allograft vasculopathy, also referred to as cardiac transplant atherosclerosis, which occurs in 15% to 20% of transplant recipients. It differs from traditional atherosclerosis in that it is a concentric and diffuse intimal hyperplastic process; the internal elastic lamina remains intact; calcification is rare; and the disease tends to develop rapidly. Although no definitive reason for cardiac allograft vasculopathy has been established, it has been suggested that it may be caused by a combination of immunologic and nonimmunologic damage to endothelial cells that results in myointimal proliferation. Intravascular ultrasound and coronary angioscopy are more sensitive diagnostic measures of cardiac allograft vasculopathy than coronary angiography. Although retransplantation currently seems to be the only definitive therapy for cardiac allograft vasculopathy, it has shown only fair results.