Pulmonary agenesis is a difficult to diagnose rare congenital condition representing failure of development of the primitive lung bud. It can have a varied age and clinical presentation. Here we present a case of a  6 month old female who was admitted with complaints of severe respiratory distress and cough. She was initially suspected as a case of right lung collapse, but the patient was eventually diagnosed to have right lung aplasia with vertebral segmentation anomaly of T8 vertebrae following a contrast enhanced tomography of the chest.