An anomalous origin for the coronary artery is a rare congenital condition with an incidence of about 0.17% based on autopsy cases. A 53-year-old man suffering from exertional angina for one month underwent coronary angiography. The left circumflex coronary artery (LCX) was found to originate from the right sinus of Valsalva. Multidetector computed tomography revealed that the LCX coursed posterior to the aorta and followed a normal course after it entered the left anterior atrioventricular groove.