Neodymium-yttrium-aluminum-garnet laser treatments were performed in 70 patients aged 62 +/- 10 (1 SD) years for incomplete malignancy-induced obstruction of the trachea or main bronchi, or both, associated with uncontrolled cough, dyspnea, atelectasis/pneumonia, and hemoptysis. Forty-three patients had been treated with surgical techniques, chemotherapy, or radiotherapy, or all three, while 27 patients were untreated before laser therapy because of acute respiratory distress. Laser treatment produced palliative improvement in 81% of the treated group (35 of 43), with survival of 4.3 +/- 3.9 months. Unsuccessfully laser-treated patients survived 0.7 +/- 0.4 month (p less than .05). Eighty-five percent of the untreated patients (23 of 27) showed postlaser improvement, with survival of 8.5 +/- 6.9 months. Unsuccessfully laser-treated patients survived 1.4 +/- 0.6 months (p less than .05). Twenty-three of the 27 previously untreated patients underwent radiation therapy after laser treatment. Laser treatments also were administered to 23 patients aged 61 +/- 13 years with complete obstruction of the main bronchi. Of this group, 17 patients had been treated and 6 had not been treated before the laser therapy. Laser treatment was successful in 47% of the treated patients (8 of 17), but there was no difference (p greater than .05) in survival between successfully and unsuccessfully treated patients (3.0 +/- 2.5 vs. 2.9 +/- 4.6 months). Similarly, laser treatment was successful in 50% of the untreated patients (3 of 6), and there was also no difference (p greater than .05) in survival between successfully and unsuccessfully treated patients (3.4 +/- 3.5 vs. 3.5 +/- 2.8 months).(ABSTRACT TRUNCATED AT 250 WORDS)