Some patients with cancer and others with benign lesions which obstruct the central airways (larynx, trachea, major bronchi) can be treated with a laser. Ninety-nine patients were considered for treatment during the first 18 months of experience with a YAG (yttrium aluminum garnet) laser at Henry Ford Hospital; 55 patients were treated 82 times. Results were satisfactory (surgery was avoided) in eight of ten patients with benign lesions. Satisfactory results (doubling of airway size with relief of dyspnea/drainage of obstructive pneumonia) were obtained in 12 of 13 patients with bronchogenic carcinoma managed initially with the laser, and in 22 of 32 (69 percent) patients with recurrent malignancies. There were five minor and seven major complications, including two deaths. We conclude that laser treatment can relieve central airways obstruction with its associated symptoms of dyspnea and infection. Avoidance of complications requires a skillful approach, careful anesthetic management, and availability of back-up posttreatment intensive care.