Anomalous origin of the left circumflex coronary artery(LCx) from the right sinus of Valsalva is the most common coronary anomaly and, generally, is considered to be benign. Nevertheless, myocardial infarction or sudden death in young patients with this coronary anomaly has infrequently been described. The LCx arises from the right sinus of Valsalva or proximal right coronary artery, courses posterior to the aorta to enter the left atrioventricular groove, and provide branches to the left lateral wall of heart. Transthoracic or transesophageal echocardiography may provide a useful diagnostic clue although coronary angiography is the standard diagnostic method. We report 2 cases of anomalous origin of the LCx from right aortic sinus with typical echocardiographic images.