Because of the development of effective drugs, surgical treatment for pulmonary tuberculosis has decreased in recent years, but there are some cases which require surgical operation in patients with drug resistant tuberculosis. Between 1979 and 1994, 52 patients with pulmonary tuberculosis underwent surgical operations for the negative conversion of drug resistant bacilli. Pulmonary resection was the principal procedure and when a patient was not tolerant to this procedure, thoracoplasty or cavernostomy was selected. Continuation of bacilli positive sputum after the operation was seen in 12 cases (23.1%). The main causes of the failure were multiple drug resistance and remaining lesions. The unsuccessful rate in the patients with bacilli completely resistant to all of the 5 main drugs (SM, KM, INH, RFP, EB) was extremely high amounting to 57.1%. When 2 or more of the 5 main drugs were effective, the unsuccessful rate was 11.1%. A total of 21 cases had tuberculous lesions remaining in the lung postoperatively, because of bilateral lesions or poor lung function. In such cases, the unsuccessful rate was 42.3%. In the 31 cases that had no remaining lesion, the rate was 9.7%. There was no unsuccessful case in the patients who had 2 or more effective drugs and no remaining lesion. We reoperated on 6 patients and 5 of them got negative conversion. In the 2 of other patients who didn't undergo reoperation, their sputum became negative after long term postoperative chemotherapy, and the other 2 patients had only a few bacilli in ther sputum postoperatively. Nine cases were able to return to normal daily life.