Objective — study of the dynamics of levels of connective tissue metabolism products in patients with multidrug-resistant tuberculosis (MDR-TB).Materials and methods. 84 patients with MDR-TB of the lungs who had a lung tissue destruction and bacterial discharge were involved in the study. Group I consisted of patients with favorable tuberculosis (n = 40); group II consisted of patients with unfavorable course tuberculosis (n = 40). The criterion for establishing a favorable flow was the discontinuation of bacterial release and closure of the cavity. The level of oxyproline fractions was investigated by the method of P.M. Sharaev in terms of mg/l. Statistical processing of the data received: Statistica Basic Academic 13 for Windows (License N 139-956-866).Results and discussion. At the beginning of treatment, the level of oxyproline free (FО) group І was 0.65 mg/l, in group II it was 1.04 mg/l, it was lower in patients from group I by 60 %. After 2 months of treatment, this level increased in both groups: in group І by 59.2 % and was 1.035 mg/l, in group II it was 28.9 % and was equal to 1.34 mg/l (p < 0.05). The protein-bound oxiproline (PBO) level at the start of treatment was 21.5 % higher in patients in group I (2.695 mg/l) compared with patients in group II (2.11 mg/l). After 2 months of treatment, its level decreased in patients from group I by 46.2 % and amounted to 1.45 mg/liter. In group II, this indicator increased by 6.9 % and amounted to 2.255 mg/l. The level of aldosterone at the beginning of treatment was higher in patients from group І, as in the beginning and after 2 months of treatment. The dynamics of its decline was more pronounced in patients from group І. Increasing the OPF level in both groups points to ongoing lung tissue destruction processes during the first 2 months of treatment. However, in group I, its level was significantly lower, indicating a more favorable course of tuberculous process in patients from group I. Low levels of PBO in group II at the start of treatment and its in significant dynamics indicate weakness of reparation mechanisms in patients from this group.Conclusions. Patients with an unfavorable MDR-TB course have a predominance of processes of destruction of the connective tissue over the repair processes. The study of connective tissue metabolism can be used as a nearly marker for predicting the effectiveness of treatment for patients with MDR-TB