A carbon dioxide laser coupled with a rigid ventilating bronchoscope has been used to treat 94 patients with symptomatic obstructing lesions of the trachea and main stem bronchi. Fifty-nine patients had malignant disease and 35 had benign disease. The results in the 35 patients with benign disease have been good except for patients with airway deformity who required subsequent reconstruction. The results in the 59 patients with malignant disease have been satisfactory. Six patients died in the immediate postoperative period, five died within 30 days of treatment, and of the remaining, 24 are alive with an average life span of 14.3 months.