Objective. Mono-resistant tuberculosis is the resistance to one of the first-line anti-tuberculosis drug, excluding the rifampicin, and poly-resistant tuberculosis means the resistance to more than one first-line anti-tuberculosis drug (izoniazid, rifampicine, streptomycine, ethambutol, with the exception of the combination of izoniazid and rifampicine. The study was conducted to assess the main peculiarities of the patients with monoresistant and poly-resistant tuberculosis and their treatment outcome. Material and methods. A cross-sectional, analytical, and retrospective study was performed, which included 124 new cases with mono-resistant and poly-resistant tuberculosis, diagnosed during 2014-2019. The patients were distributed into two groups: the 1st group included 85 (68.5%) cases with mono-resistant tuberculosis and the 2nd group – 39 (31.5%) cases with poly-resistant tuberculosis. Results. Among 85 cases from the 1st group, 69 (81.2%) cases were resistant to streptomycine, 15 (17.5%) to izoniazid, and 1 (1.2%) to ethambutol. Among 39 cases of the 2nd group: 32 (82.0%) were resistant to izoniazid + streptomycine and 7 (18.0%) to isoniazid + ethambutol + streptomycine. The peculiarities of the patients did not show statistical differences in terms of the men/female rate and the affected age groups. Most of them had a socially-economical vulnerable state and high-risk factors. Patients were more frequently detected through the passive case-finding. No differences, according to the localization and extensibility, between the groups were established. The treatment success was registered in 66 (77.6%) cases of the 1st group and 31 (79.5%) cases of the 2nd group. The death occurred in 10 (11.8%) cases of the 1st group and 6 (15.4%) cases of the 2nd group. Conclusions. Within the mono-resistance predominated resistance against the streptomycine and in poly-resistance was noted the resistance against the isoniazid + streptomycine. No differences in general characteristics, social-economical status, high-risk factors, localization, and extensibility of tuberculosis were found. The treatment outcome was suboptimal with a high rate of death in both groups. Individualized approach should be used in all patients for the improvement of the treatment outcome