Unilateral Pulmonary aplasia with absent right pulmonary artery is a rare disorder, caused by the developmental arrest of primitive lung during embryonic life. It’s a complete absence of lung parenchyma vasculature and its main bronchus. The most common variant consists of carina and main stump bronchial stump with the absence of distal lung. It is frequently associated with many other congenital disorders like VACTERL syndrome (V-vertebral anomalies, A-anal atresia, C- cardiovascular anomaly, T- tracheosophageal fistula, E- esophageal atresia R-renal anomalies L- limb defects) and cardiac anomaly. These patients usually present with respiratory distress. Here we are presenting a case of a 2-month-old male infant suffering from unilateral lung aplasia with absent right pulmonary artery.