BACKGROUND: It is said that tuberculous pleuritis responds well to anti-tuberculous drug in general, so no further aggressive therapeutic management is unnecesarry except in case of diagnostic thoracentesis. But in clinical practice, we often see some patients who need later decortication due to dyspnea caused by pleural loculation or thickening despite several months of anti-tuberculous drug therapy. Therefore, we want to know the clinical difference between a group who received decortication due to complication of tuberculous pleuritis despite of anti-tuberculous drug and a group who improved after 9 months of anti-tuberculous drug only. METHODS: We reviewed 20 tuberculous pleuritis patients(group 1) who underwent decortication due to dyspnea caused by pleural loculation or severe pleural thickening despite of anti-tuberculous drug therapy for 9 or more months, and 20 other tuberculous pleuritis patients(group 2) who improved by anti-tuberculous drug only and had similar degrees of initial pleural effusion and similar age,sex distribution. Then we compared between the two groups the duration of symptoms before anti-tuberculous drug treatment and pleural fluid biochemistry like glucose, LDH, protein and pleural fluid cell count and WBC differential count, and we also wanted to know whether there was any difference in preoperative PFT value and postoperative PFT value in the patients who underwent decortication, and obtained following results. RESULTS: 1) Group 1 patients had lower glucose level{63.3+/-30.8(mg/dl)} than that of the group 2{98.5+/-34.2(mg/dl), p<0.05}, and higher LDH level{776.3+/-266.0(IU/L)} than the group 2 patients{376.3 +/-123.1(IU/L), p<0.05), and also longer duration of symptom before treatment{2.0+/-1.7(month)} than the group 2{ 1.1 +/-1.2(month), p<0.05)}, respectively. 2) In group 1, FVC changed from preoperative 2.55+/-0.80(L) to postoperative 2.99+/-0.78(L)(p<0.05), and FEV1 changed from preoperative 2.19 +/- 0.70(L/sec) to postoperative 2.50+/-0.69(L/sec) (p<0.05). 3) There was no difference in pleural fluid protein level(5.05+/-1.01(gm/dL) and 5.15+/-0.77 (gm/dl), p>0.05) and WBC differential count between group 1 and group 2. CONCLUSION: It is probable that in tuberculous pleuritis there is a risk of complication in the case of showing relatively low pleural fluid glucose or high LDH level, or in the case of having long duraton of symptom before treatment. We thought prospective study should be performed to confirm this.