A simplified technique for repair of type II and III truncus arteriosus applicable in neonates is described. The method is particularly useful in those patients in whom the pulmonary artery orifices arise from the posterior wall of the truncal root. Advances in two-dimensional echocardiography have provided an accurate means of determining the exact anatomy preoperatively. At operation, isolation of the pulmonary orifices on a button of posterior truncal wall is accomplished by complete division of the main truncal root. Primary closure of the new ascending aorta is made possible by extensive mobilization of the aorta and pulmonary orifices. Early postoperative follow-up indicates that the use of a new absorbable suture for primary repair of the aortic root allows for normal growth.