From January 1987 to May 1988, 32 cases with tracheobronchial lesions were treated with Nd-YAG laser. Complete restoration of the airway was achieved in one case of leiomyoma, adenoma, carcinoid and mucous epithelioma each, 2 cases of polyp and 7 cases of granuloma. Significant restoration was seen in one case of granuloma, 2 cases of hematoma and papilloma, each, 3 cases of amyloidosis and partial restoration in one case of granuloma. The remaining 10 cases with squamous cell carcinoma and adenocarcinoma with severe airway obstruction were treated by Nd-YAG laser for palliative purpose only. Four of them revealed significant remission and 6 responded with partial remission. No severe complication was observed during or after the procedures. Nd-YAG laser treatment provides a new curative method avoiding resection of the lung in benign lesions and a palliative therapy for unresectable obstructive malignant tumors.