Cardio-vocal or Ortner's syndrome is dysphonia or hoarseness resulting from left recurrent laryngeal nerve palsy caused by a mechanical effect on the nerve due to enlarged cardiovascular or mediastinal structures. It was first described in adults with left atrial enlargement due to mitral stenosis. To date, there are a paucity of reports regarding its occurrence in infants and children. We report hoarseness and left vocal cord paresis in an infant with a large left-to-right shunt associated with a patent ductus arteriosus. The history of Ortner's syndrome is presented, its pathogenesis described, and previous reports of its occurrence in infants and children reviewed.