We evaluated the effectiveness of high dose rate (HDR) endobronchial irradiation for palliation of malignant airway obstruction. Between May 1989 and February 1992, 39 patients were treated in our department. Thirty-two patients (82 percent) had primary lung neoplasms and 7 (18 percent) had metastatic disease. Thirty-three patients (85 percent) had prior external irradiation (either alone or in combination with chemotherapy), and 9 patients (23 percent) received laser excision before treatment. Of the 39 patients, 14 (36 percent) presented with hemoptysis, 20 (51 percent) with cough, 15 (38.5 percent) had dyspnea, and 15 patients (38.5 percent) had pneumonia or atelectasis. There were 57 applications performed in the 39 patients. Patients with hemoptysis had 93 percent complete response (CR), 20 percent with cough had CR; 60 percent improved (partial response [PR]); no response was seen in 20 percent. Atelectasis and pneumonia resolved in 20 percent of patients. Eighteen patients (46 percent) underwent a second procedure and were evaluated for objective response; 34 percent had CR, 44 percent had PR, and 22 percent did not respond. There were two acute (one bronchospasm, one pneumothorax) and three late (two strictures, and one exsanguination) complications. In our experience, HDR was highly effective in the palliation of airway symptoms caused by malignant tumors, with acceptable toxicity.