The paper presents the data of examination of three groups of patients with pulmonary tuberculosis: 25 with a relatively favorable course of the disease, 26 with acutely progressive tuberculosis, pneumoperitoneum along with chemotherapy was used in complex therapy in 10 of them. The parameters of lipid peroxidation were estimated in the condensate of the expired air from patients before and 3 months after inpatient therapy. Irrespective of the type of the course of the disease, patients with tuberculosis were found to have a marked increase in the elimination of lipid peroxidation products, as well as deficiency of antiradical defense factors, which also preserved after therapy. The use of pneumoperitoneum in the complex therapy of patients with acutely progressive tuberculosis reduced the level of lipid peroxidation products more significantly.