A 9-month-old girl presented with cyanosis after correction of total anomalous pulmonary venous return (TAPVR) to the coronary sinus in the neonatal period. During corrective surgery, the right superior vena cava (RSVC) was damaged and re-anastomosed to the right atrium. Echocardiography showed increased flow velocity in the pulmonary venous confluence. Therefore, pulmonary venous obstruction was suspected. However, subsequent cardiac MRI revealed a stenosed RSVC as well as a dilated left superior vena cava (LSVC) draining from the left innominate vein into the pulmonary venous confluence. The re-recruited LSVC drained deoxygenated blood into the systemic circulation, causing cyanosis. After uncomplicated placement of a stent in the narrowed RSVC and occlusion of the LSVC, transcutaneous saturations normalised immediately.