Eleven infants under the age of 12 months who developed symptoms due to scimitar syndrome have been seen at St. Louis Children's Hospital. The average age at presentation was 2.5 months, and all had congestive heart failure with pulmonary hypertension (PA systolic= 76±21 mmHg). All had hypoplasia of the right lung; 6 of 11 had a large anomalous systemic artery to the right lower lobe. Four of 11 patients died: one due to prematurity, one following ligation of the anomalous systemic arteries only, one following repair of hypoplastic left heart syndrome, and one due to persistent severe pulmonary hypertension after repair. One patient underwent right pneumonectomy as his "definitive" repair and is a long-term survivor. Six others underwent an "anatomic" sort of repair consisting of baffling the anomalous venous return through an atrial septal defect into the left atrium and ligation of the systemic arterial vessels entering the right lung. Two of these baffling procedures were done leaving the anomalous pulmonary vein connected to the inferior vena cava and running the baffle from that point to the atrial septal defect; both of these patients suffered occlusion of the pulmonary vein/baffle and ultimately required right pneumonectomy. The other four had the vein detached and moved cephalad to the posterior mid-wall of the right atrium and then baffled to the atrial septal defect. One of these patients suffered occlusion of the vein resulting in pneumonectomy; another patient with pulmonary vein stenosis of the left lung ultimately required lung transplantation. We conclude that infants presenting with scimitar syndrome during infancy are best treated with detachment of the anomalous pulmonary vein from the inferior vena cava, moving it to a position closer to the left atrium so that a short baffle can be constructed to the left atrium through the atrial septal defect.