Two children with an anomalous origin of one pulmonary artery from the innominate artery are reported. One was a 15-month-old boy presenting with respiratory distress. He had a right aortic arch and his left pulmonary artery originated from the innominate artery. The other was a 1-month-old girl presenting with congestive heart failure. She had a left aortic arch and her right pulmonary artery originated from the innominate artery. An understanding of the embryological pathogenesis of these anomalies has significant therapeutic implications.