Significant airway obstruction may complicate the natural and surgical history of infants with congenital heart diseases. Airway obstruction occurred in 12 infants who had operations for congenital heart disease. In all cases tracheography demonstrated the cause of airway obstruction. Significant mortality (5/12, 41.7%) and morbidity in this group of infants were the result of airway obstruction. To reduce the complications caused by airway obstruction in infants with congenital heart disease, we recommend (1) preoperative identification of patients with potential airway obstruction, (2) preoperative tracheography in high-risk infants, (3) appropriate choice of the surgical procedure, especially when insertion of a prosthetic conduit is required, (4) early recognition of the problem during the postoperative period, (5) prompt diagnosis by postoperative tracheography, with or without angiography, and (6) therapy directed at the cause of airway obstruction.