[en] Two cases of adult asymptomatic right aortic arch with an aberrant subclavian artery are reported. They were discovered at time of coronary surgery. Preoperative coronary arteriography failed to demonstrate the anomalies. In one case, the right arch was suspected on chest x-ray and preoperative barium oesophagography. In one case, the proximal suture of one saphenous bypass graft was performed on the left common carotid artery. Right aortic arch is a malformation rarely discovered in adults. It generally produces no symptoms when not associated with cardiac disease.