Photodynamic therapy with photosensitizers is a new method of treating malignant tumors. In the area of bronchoscopy it is employed for the selective therapy of early carcinomas at central localizations. We report on our first attempts at treatment with hematoporphyrin derivative in an inoperable patient. The modalities of irradiation and the recurrence-free progress of, to date, 2.5 years, are described.