Over a 15-year period, 277 diagnostic bronchoscopic procedures were carried out at the Winnipeg Children's Hospital using rigid bronchoscopic instrumentation. The objective of the review is to examine contribution to final diagnosis made by the procedure. The patient population included 60% male and 40% female patients ranging from the first day of life to 18 years (mean age, 6 years). Indications for bronchoscopy fell into two large groups, including 60% of patients with evidence of lower airway disease and 30% of patients with evidence of upper airway obstruction. In patients with upper airway obstruction, half were found to have a congenital underlying cause and half were due to an acquired lesion. In 85% of patients, a specific diagnosis was reached and this proved to correlate positively with the preoperative diagnosis in 80% of patients and negatively in 20%. Definitive treatment in patients with upper airway obstruction included surgical intervention in one third of patients. Patients with lower airway disease were diagnosed as having consolidation in 43%, atelectasis in 39%, and bronchiectasis in 18%. Disease localized most frequently to the left lower and right upper lobes and in only 10 of 168 patients was a congenital cause determined. Among 168 patients, 30 had surgical treatment as the definitive management with the majority of patients treated medically. Bronchoscopy was shown to contribute to diagnosis in 88% of patients examined. Bronchoscopy was carried out with a complication rate of 3% and no mortality.