Of 131 patients with pulmonary infections due to Mycobacterium avium-intracellulare, 124 had excisional surgery plus chemotherapy. Seven had definitive thoracoplasties. Postoperative complications of various degrees developed in 24% of those who had surgery. Bronchopleural fistulae requiring thoracoplasties occurred in seven patients. Nine patients died in the postoperative period. The sputum of 93% of the patients became negative for M. avium-intracellulare, and 5% of the patients had bacteriologic relapse. Only two of the 122 patients who survived surgery died from progressive pulmonary infection due to M. avium-intracellulare.