Coronary artery disease (CAD) is a well-known complication of mediastinal irradiation. We report a case of subocclusive ostial stenosis of the left main coronary artery, in a 27 years old man, who had been irradiated 14 years before for a stage 4 Hodgkin's disease. Among the 68 reported cases of CAD attributed to radiotherapy, 11 involved an ostial stenosis of either right coronary artery, or left main coronary artery or both. Thus mediastinal irradiation seems to be a definite cause of ostial coronary artery stenosis; several types of myocardial revascularization have been suggested for this kind of CAD.