The purpose of this research was to determine the dependence of the tubercular inflammation activity of varying duration of the disease and drug resistance. Morphological activity of inflammation in 161 patients with drug-resistant and 149 patients with retaining its high sensitivity was studied. Morphological assessment of the activity of specific changes in tuberculosis was carried out according to the B.M. Ariel classification (1998). It was revealed at morphologic study of resection material that the greatest activity of specific inflammation and its prevalence outside the main lesion was in the group of patients limited with drug resistance tuberculosis. It was noted the prevalence of IV-V degree of morphological activity of tubercular process in the study group by 3 times over the control group with disease duration of more than 1 year. Predominance of widespread active specific changes (IV degree) was determined in 2 times for the first educed patients of basic group with drug-resistant above a control group. This is due to increasing the number of patients with cavernous and fibro-cavernous tuberculosis.Thus, it is necessary to operate patients with drug-resistant tuberculosis as soon as possi-ble after adequate specific therapy and the presence of the signs of stabilization process, because as the full stabilization of tuberculosis process did not achieve according to the morphological study of surgical specimens in the preoperative period. Further specific therapy becomes futile due to the rise of drug resistance, the emer-gence of new drug-resistant strains of Mycobacterium tuberculosis.