A new surgical method for repair of anomalous origin of the left coronary artery from the pulmonary trunk is described. The principle of the proposed technique is to transmit the oxygenated blood to the anomalous left coronary artery through surgically created aortopulmonary window and the internal tunnel created in the main pulmonary trunk. A 2-year-old boy in whom this anomaly was associated with mitral regurgitation caused by papillary muscle dysfunction was successfully treated by this new surgical method, and the deformed mitral valve was concomitantly replaced by a Hancock porcine xenograft.