Forty-five infants and children with intrathoracic tracheobronchial obstructions requiring surgical treatment are reported. Segmental stenosis of the trachea is defined as involvement of less than one half the length of the airway, which affected six infants. Elongated stenosis involving more than one half the length of the trachea was seen in 12 infants, and complete annular cartilage rings, along the entire length of the trachea, were present in 11. Severe tracheomalacia occurred in six infants associated with aortic arch anomalies and in nine infants with esophageal atresia. Segmental tracheal resection was performed in 17 cases (two after failure of a rib cartilage graft), and anastomotic stricture developed in three. These three anastomotic strictures were resected, resulting in an excellent airway in two and restricture in one. Rib cartilage grafts were used in five patients: two of three with elongated stenosis with complete tracheal rings required subsequent resection, and one of two infants with tracheomalacia had excellent outcome. Approximately 50% of an infant's trachea can be resected, but rib cartilage grafts should be used for elongated stenosis. Resection of bronchial stenosis in two patients resulted in a widely patent bronchus. From this experience primary segmental tracheobronchial resection and re-resection of recurrent stenosis are highly successful. Anastomotic stricture is due to tension at the suture line and suture material inciting a fibrotic reaction. Rib cartilage grafts amounting to 25% or less of the circumference of the airway readily resurfaces with adjacent epithelium, but when 30% or more of the circumference is rib graft, epithelialization may be impaired.