Neodymium-yttrium-aluminum-garnet (Nd-YAG) laser was clinically introduced to the treatment of tracheobronchial lesions 10 years ago. Since then, the apparatus of the laser therapy and the flexible bronchoscopy have been improved, and the indication for its treatment has been established. Nd-YAG laser is useful at the field of the treatment of the tracheobronchial stenotic or obstructed lesions. But various complications occur, because of the lesions occupying in the narrow tracheo and bronchial lumen. In our institute, 83 cases have been treated in 196 sessions (from one to fifteen sessions per patient) for the past ten years. The stenotic or obstructed lesions were divided into three etiologies, 64 cases with malignant lesion, 8 cases with post operative granulation at the suture line and 11 cases with benign lesion. All procedures were performed under local anesthesia by using flexible bronchoscope. Among them, complications were noticed in eleven cases. They involved hemorrhage (6 cases) and respiratory disturbances (2 cases) during operative period, and massive hemorrhage (2 cases) and edema of the tumor (1 case) in the adjacent period of laser treatments.