Isolation of the left common carotid or left innominate artery from the aortic arch is rare. A six week malformed infant with a right aortic arch had isolation of a left innominate artery and connection to the pulmonary artery by a left ductus arteriosus. A right ductus arteriosus had been ligated. Another infant with a right aortic arch and ostium primum atrial septal defect was shown to have an aberrant left subclavian artery arising from the lower descending aorta. The left common carotid artery filled retrogradely and drained into the pulmonary artery by a left ductus arteriosus. This abnormality has not been reported before.