Aorto-left ventricular tunnel is a rare congenital cardiac anomaly, consisting of a short abnormal pathway, usually from a sinus of Valsalva into the left ventricular cavity. It is usually diagnosed with echocardiography. We report a case of a newborn presenting with heart murmur and rapid progression to heart failure and left ventricular enlargement due to an aorto-left ventricular tunnel. Despite successful closure of the tunnel, the patient required a Ross procedure due to progressive aortic disease.