Although tracheoesophageal fistula and esophageal atresia (TEF-EA) are surgically correctable, late respiratory complications have been reported. We administered a respiratory and gastrointestinal symptom questionnaire and performed standard pulmonary function tests (PF T's) and methacholine challenge testing on an unselected group of 25 subjects with TEF-EA who underwent surgery at our institution between 1963 and 1985. Results were compared to predicted normals, as well as 10 sibling controls. While the mean values of lung function test results for the TEF-EA group were within the normal range, they were significantly different from their siblings. Thirteen of the 25 TEF-EA group (52%), but none (0%) of the controls, had abnormal pulmonary function. This was classified as restrictive in 9 (36%), obstructive in 3 (12%), and mixed in 1. In addition, airway hyperreactivity [defined as a positive methacholine challenge (PC20 < or = 8 mg/mL)], was found in 6 of 18 TEF-EA subjects and 4 of the 9 controls who were evaluated. Comparison of TEF-EA subjects with normal and abnormal PFTs showed no difference in the incidence of tracheomalacia, esophageal strictures or dilatation, recurrent pneumonias, or gastroesophageal reflux. The respiratory symptom score in the subjects and controls was similar, and did not correlate with abnormal pulmonary function. The cause of the pulmonary function abnormalities remains unexplained.