OBJECTIVE: Cavitary lesion in pulmonary tuberculosis sometimes makes problems in the course of treatment. Especially, retreatment cases tend to respond poorly to current antituberculosis agents. So, authors tried to render a guideline for clinical approach toward cavitary lesions in pulmonary tuberculosis. METHODS: Retrospective analysis of 33 pulmonary tuberculosis patients with cavitary lesions was made. All the patients had got treatment at National Masan Tuberculosis Hospital from Jan. 1995 to Aug. 1995. RESULTS: The ratio between male and female was 10:1. Age distribution was 69.7% in 3rd and 4th decades. The locations of cavitary lesion were 60.6% in right upper lung field and 36.4% in left upper lung field. In the extent of disease, there were 12 cases(36.4%) in moderate advanced and 21 cases in far advanced. Cavitary lesions were closed in 5 cases and remained in 28 cases. In the cases of closed cavity, it was happened within 10.6+/-4.72 months after they took treatment, the size of cavity was 35.5 +/-17.1 in long diameter, 27.0+/-12.2 in short diameter and 4.6+/-2.1 mm in wall thickness. In the cases of remained cavity, the size of cavity was 31.9 +/-12.3 in long diameter, 21.0+/-9.8 in short diameter and 5.04+/-2.0 mm in wall thickness. In terms of negative conversion, it took 3.8 +/-2.17 months in the case of closed cavity but it was happened within 5 months for only 4 patients in the case of remained cavity. In the point of past medication history, there was none in closed cavities but there were none in 1 case, once in 3 cases, two times in 9 cases and more than three times in 13 cases among remained cavitary lesions. CONCLUSION: In the retreatment cases of pulmonary tuberculosis with cavitary lesions, they tend to respond poorly to current antituberculosis agents. So, if the lesions are localized, operative intervention may be a proper method as adjunctive treatment.