Coronary artery disease is a common and particularly severe complication of cardiac transplantation because it may cause progressive destruction of the graft by acute or chronic ischemia. The ischemia is usually silent because of cardiac denervation. Cardiac failure related to graft dysfunction, asymptomatic infarction on the ECG, or sudden death, are sometimes the only signs of severe coronary disease. The prevalence of coronary lesions has been evaluated by coronary angiography at nearly 25% at 2 years and 50% at 5 years. The distribution and morphology of the lesions are characteristic: diffuse concentric, irregular and occlusive, predominantly distal stenoses, without a distal and usually without a collateral circulation. The histological features are variable: the association of medial necrosis, severe endothelial lesions and intense parietal inflammation are suggestive of acute arteriolitis, often present during acute rejection, may be related to a common pathological process. Diffuse obliterative arteriolar lesions with concentric proliferation of medial smooth muscle are the usual appearances in transplant patients who have died or been retransplanted. There is no non-invasive diagnostic method sufficiently sensitive of specific which justifies the practice of many groups of systematic annual coronary angiography in transplanted patients. The pathogenesis is poorly understood and probably multifactorial: disorders of lipid metabolism, immunological factors, the atherogenic role of Cytomegalovirus infection. The absence of an identifiable risk factor makes preventive measures difficult. The evolutive risk justifies retransplantation in selected patients, the results of which are less satisfactory but which reduces the risk of acute coronary events and sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)