Photoradiation therapy is a new technique being investigated for the treatment of solid malignant tumors. In this study, 17 patients with advanced, recurrent, biopsy-proven malignant lesions of the trachea or main-stem bronchus were treated by photoradiation therapy. Patients received hematoporphyrin derivative intravenously three days prior to light therapy. The light was delivered from a fiberoptic fiber attached to the output beam of a dye laser (633 +/- 3 nm). The fiber was passed through the large channel of a bronchoscope (Olympus BF 2T). Of the 17 patients, two had no measurable response to the photoradiation therapy, six had partial necrosis of the tumor, seven patients had a greater than 50 percent reduction in the intraluminal volume of tumor, and two were lost to follow-up. Survival ranged from 5 to 210 days (median survival, 40 days). Complications of the treatment were significant in this group of advanced-stage patients and included excessive secretions, fever, pneumonia, and abscess formation.