Between December 1980 and April 1986 at our institution, 38 patients with cancer that involved the tracheobronchial tree (a total of 40 carcinomas) completed at least one course of hematoporphyrin derivative phototherapy. A complete response occurred in 13 patients (with 14 carcinomas). Eleven of these carcinomas did not recur during follow-up periods that ranged from 3 to 53 months. Three carcinomas recurred at 9, 12, and 35 months, respectively. For 26 carcinomas, the response was less than complete, and alternative therapy was necessary. The carcinomas in patients with a complete response were radiographically occult, were less than 3 cm2 in surface area, and appeared superficial at bronchoscopy. Our experience supports the use of hematoporphyrin derivative phototherapy as an alternative to surgical resection in carefully selected patients.