Aortopulmonary (AP) window is a communication between the main pulmonary artery and the ascending aorta in the presence of two separate semilunar valves. AP window is classified into three types: Proximal defect (type I), Distal defect (type II), and Total defect (type III). Although surgical complications of isolated AP window are uncommon, they may involve residual shunt or branch pulmonary artery stenosis. The presence of associated congenital heart defects with AP window increases the risk of surgical complications that may result in recurrent arch obstruction. This chapter will examine the surgical complications in the repair of AP window and offer solutions to avoid missteps.