One patient with chronic exertional angina, not significant electrocardiographic signs of myocardial ischemia at exercise stress test and recent onset of angina at rest underwent coronary arteriography. A second one with known severe aortic stenosis underwent cardiac catheterization and coronary arteriography because of effort chest pain and syncope. A single coronary artery originating respectively from the right and from the left sinus of Valsalva but without significant coronary stenosis was detected in both patients. This entity is a quite uncommon finding of relevant interest if surgical treatment is required and good prognosis if not associated with additional cardiac anomalies.