Coronary arteries anomalies may be part of complex congenital malformations of the heart or be an isolated defect. In our anatomic collection of congenital heart disease, an isolated anomalous origin of coronary arteries was observed in 27 of 1,200 specimens (2.2%): left coronary artery from pulmonary trunk in five, origin from the wrong aortic sinus in 12 (both right and left coronary artery from the right sinus in four and from the left sinus in seven, left coronary artery from the posterior sinus in one), left circumflex branch from right aortic sinus or from very proximal right coronary artery in three, high takeoff of right coronary artery in three, stenosis of the coronary ostia attributable to valvelike ridge in four. In 16 (59%) patients (12 males and 4 females, age ranging from 2 months to 53 years; median, 14), the final outcome was sudden death; it occurred in all cases of left coronary artery origin from right aortic sinus, in 43% of right coronary artery origin from left aortic sinus, and in 40% of the left coronary artery from the pulmonary trunk. Sudden death was precipitated by effort in eight (50%) and was the first manifestation of the disease in eight (50%); previous symptoms consisted of recurrent syncope in four, palpitations in three, and chest pain in one. Five patients who died suddenly during effort were athletes. In conclusion, (1) more than half of our postmortem cases with anomalous origin of coronary arteries died suddenly, (2) all but two patients with sudden death had anomalous coronary artery origin from the aorta itself, (3) the fatal event was frequently precipitated by effort, (4) palpitations, syncope, and ventricular arrhythmias were the only prodromic symptoms and signs. Recognition during life of these coronary anomalies, by the use of noninvasive procedures, is mandatory to prevent the risk of sudden death and to plan surgical correction if clinically indicated.