The association of aortopulmonary window and tetralogy of Fallot is rare. The aortopulmonary window lies usually between the left side of the ascending aorta and the right wall of the pulmonary artery just anterior to the origin of the main pulmonary artery. Recently, we experienced a case of aortopulmonary window associated with tetralogy of Fallot in a 4 years old male. Operation was done under the Impression of the tetralogy of Fallot. On operation, the anomaly was confirmed as aortopulmonary window[type 1] and tetralogy of Fallot. The aortopulmonary window was closed with Gortex patch via the main pulmonary artery and tetralogy of Fallot was repaired. Postoperative course was uneventful.