Interrupted aortic arch associated with an aortopulmonary window is a rare congenital malformation that requires an early diagnosis and surgical treatment to avoid irreversible pulmonary vascular changes. We describe herein successful one-stage repair in a neonate without the use of pericardium or other prosthetic material. Use of a transaortic approach permitted both accurate planning of the appropriate size of pulmonary trunk flap and also facilitated easy repair of the aortopulmonary septal defect. The growth potential of both great arteries was optimized.