Background: Almost previous studies have evaluated the pulmonary impairment in pulmonary function test (PFT) during and after pulmonary tuberculosis (TB). The aim of this study was to evaluate the change of lung function by means of quantifying the lung function in the same individuals both before and after the occurrence pulmonary TB, as well as the different change of lung function according to disease extents based on number of lobes involved on chest computed tomography. Methods: The changes of lung function and predictors from patients with pulmonary TB according to disease extents were evaluated. Localized and advance pulmonary TB was defi ned as one or less and two or more involvement of lobe by TB, respectively. Results: In total, 41 patients were included. The patients were predominantly male (70%) and old (median age, 63.5 years, IQR, 56.5-69.8 years). The advanced TB group had a median decline in FEV1 of 0.3L (0.2-0.6) and the localized TB group had a median decline of 0.1L (0.0-0.2) (△FEV1, % predicted, 14.5% (7.3-25.1) vs. 5.6% (2.8-9.7)). For FVC, the median decline in the advanced TB group was 0.45L (0.2-0.5) compared with 0.2L (0.0-0.3) in the localized TB group (△FVC, % predicted, 11.5% (8.9-25.6) vs. 4.1% (1.4-8.9). In multivariate analysis, remarkable lung function decline of FEV1 and FVC was independently associated with advanced TB. Conclusions: The localized pulmonary TB does not lead to significant pulmonary impairment. However, further lung function decline occurred in cases of advanced pulmonary TB. In addition, advanced pulmonary TB was independently associated with remarkable lung function decline in FEV1 and FVC after pulmonary TB.