We treated 1,000 patients with the Nd:YAG laser. The rigid bronchoscope was used in 1,280 (92 percent) of the treatments, with patients almost always under general anesthesia; 116 (8 percent) treatments were performed with the flexible fiberoptic bronchoscope alone, with the use of local anesthesia. In almost all cases of benign tumors and in many carcinoid tumors, the treatment was curative. In genuine nonmalignant tracheal stenoses, laser therapy was curative in 34 out of 81 cases. In malignant tumors, the laser improved airway gauge 92 percent of the time. Cumulative survival was 50 percent (+/- 3 percent) at six months and 26 percent (+/- 3 percent) at one year. Following palliative laser therapy, eight patients with bronchogenic carcinoma appearing to be inoperable did have surgery and ten underwent less extensive surgery than expected. Results confirm the usefulness and safety of this relatively new method in the treatment of obstructive lesions of the tracheobronchial tree.