We report a case of fistula between the descending aorta and the left atrium with associated aortopulmonary window and secundum atrial septal defect. No previous reports of such association have been found in the literature. A 5-month-old infant presented with heart failure from the age of 2 weeks. Echocardiography confirmed the presence of an aorto-left atrial fistula, aortopulmonary window, and atrial septal defect. The diagnosis was additionally supported by computed tomography. The entity aorto-left atrial fistula is rare. It is mostly acquired and usually between the ascending aorta and the right atrium or right ventricle or left ventricle. We do not know about all the associated anomalies, which have implications in management. There is a case report of ascending aorto-left atrial fistula associated with bicuspid aortic valve and anomalous origin of coronaries. Here we are reporting a case of descending aorto-left atrial fistula associated with aortopulmonary window.