We report a 67-years-old patient with angina pectoris and positive treadmill test. In the coronary arteriography the left coronary artery arose from the right coronary sinus of Valsalva through an independent ostium and followed a retroaortic course. Coronary artery disease was no demonstrated, so we thought that the myocardial ischaemia shown in the treadmill test, was due to the anomalous origin of the left coronary artery. Surgical treatment was recommended.