Pulmonary artery sling is a rare congenital vascular anomaly in which the left pulmonary artery arises from the posterior aspect of right pulmonary artery and courses to the left behind the tracheal bifurcation and in front of the esophagus to reach the left lung hilum and forms a sling around the trachea. We are reporting a case of a two-month-old infant with biliary atresia referred for screening echocardiogram before surgical procedure. The patient had no history of respiratory distress or dysphagia. Echocardiography revealed aberrant left pulmonary artery arising from the right pulmonary artery with no pulmonary stenosis probably pulmonary artery sling. Diagnosis was confirmed on cardiac computed tomography angiography. On minor class of risk stratification patient was allowed to proceed for surgical procedure for biliary atresia as standard risk of anesthesia.