The malformation consisted of persistent left SVC terminating in left atrium, absence of coronary sinus, and atrial septal defect is considered as a developmental complex anomaly. We observed such a case associated with partial atrioventricular canal defect and common atrium. We operated it by intraatrial roofing [tunneling] along its course of the posterior wall of the left atrium using bovine pericardial patch, which was designed to contain some of thebesian veins, thereby, left superior vena caval and some coronary venous blood would be drained into venous side. Associated lesions were also corrected.