In 86 patients suffering from different forms of pulmonary tuberculosis, we performed analysis of bronchoalveolar lavage obtained' from the affected and contralateral lung. We evaluated the cellular contents, spontaneous and stimulated with the killed BCG-culture NST-test with alveolar macrophages, as well as the contents of the dienic conjugates and the activity of some enzymes of antioxidant protection (AOP), i. e., ceruloplasmin, superoxiddismutase, catalase, glutation-peroxidase, glutation-reductase. It has been shown that even in acute limited cases, the whole lung tissue was involved into the infection process. The activation of the AOP system, being increased in parallel with the disease becoming more severe, promoted the inflow of phagocytic cells and intensification of the oxygen-dependent metabolism in them. Severe intoxication and massive release of the bacilli initiated gradual decompensation of the AOP system of intact lung tissue, thus being one of the facts predisposing to bronchoobstruction developing in tuberculosis; patients. The reaction of the AOP system in the vicinity of the inflammatory locus in principle is less differentiated, while its insufficiency contributes into the development of extensive non-specific inflammatory changes of the bronchial mucosa.