Fifty-four patients underwent repair of atrial septal defects through a right thoracotomy between January 1985 and December 1991. The average patient was 5.7 years old. Defects repaired included 51 secundum, 2 sinus venosus, and 1 ostium primum defect. The average bypass time was 24 minutes. There was no operative or late mortality, and no morbidity directly related to the thoracotomy approach. The right thoracotomy incision is a safe and effective alternative to a median sternotomy for repair of atrial septal defects. The cosmetic result is superior to that of median sternotomy or bilateral submammary incision.