Single arterial trunk, also called persistent truncus arteriosus, is one of the less common cyanotic conditions in newborns. Because of abnormal embryologic development of the conotruncal region, the three major circulations, coronary, pulmonary, and systemic, arise from a common arterial structure which originates above a ventricular sepal defect. The newborns quickly develop congestive cardiac failure because of pulmonary overcirculation. The pulmonary vaculature being exposed to systemic pressure levels quickly develops pulmonary vascular changes. Hence these newborns are operated upon with closure of the ventricular septal defect and placement of a right ventricular to pulmonary artery conduit. With the early recognition of the condition, often by fetal echocardiograpy, prompt referral, and improved operative and perioperative care, the results are excellent. Many patient will need replacement of the conduit as they grow.