The aim of the study was to evaluate structural changes in the lung tissue in patients with pulmonary tuberculosis (TB) and coexisting obstructive pulmonary disease (COPD) using highresolution computed tomography (HRCT) and to analyze an influence of CT lesions on the lung function. Materials and methods. One hundred and sixteen TB patients were involved. HRCT with Nodule Analysis and Lung Volume Analysis additional soft ware, spirometry, body plethysmography and measurement of diffusing capacity of the lungs for carbon monoxide were performed in all patients. We used descriptive statistics and Spearman’s correlation analysis. Results . Patients with TB + COPD (n = 23) had extensive (> 3 lung segments) specific changes in the lungs more likely than patients without COPD (n = 93): 83% and 44%, respectively; p < 0.05. Patients with TB + COPD also had higher total volume of TB lesions (p < 0.05) and emphysema (61 and 30%, respectively; p < 0.05) on CT scans. Patients with TB + COPD had panlobular emphysema (17%) more often than other variants of emphysema. Patients without COPD had predominantly centrilobular emphysema (13%); panlobular emphysema was seen in a few cases (2%). Ventilation and gas exchange parameters were related to the volume of TB lesions on CT scans. An increase in emphysema volume on CT scans negatively affected the airflow limitation in all patients and deteriorated lung hyperinflation and lung diffusing capacity in patients with TB + COPD. Conclusions. TBspecific pulmonary lesions were significantly more prominent in patients with TB + COPD. TBspecific pulmonary lesions could worsen ventilation and gas exchange. More extended emphysema on CT scans could worsen bronchial obstruction in all patients, deteriorate lung hyperinflation and diffusing capacity in patients with TB + COPD.