Over a 4-year period in four of 61 patients (6.5%) who survived lung transplantation, pulmonary tuberculosis developed at a mean of 7.5 months (range 3 to 13 months) after operation. Clinical and radiologic features were atypical. Definitive bacteriologic diagnosis, which was established on bronchial, sputum, and pleural fluid samples, may be delayed by the concomitant presence of other infective organisms and the necessity for repeated sampling. All patients were treated successfully with antituberculous chemotherapy, but one patient also required lobectomy. At a mean follow-up of 2.25 years (range, 1 to 3 years), three patients are free of active disease, and one patient had a recurrence at 2 years. Tuberculosis in transplanted lungs is an uncommon but serious infection that may elude diagnosis but respond well to treatment.