Objective — to assess the impact of diabetes mellitus on anti-tuberculosis treatment outcome in patients with pulmonary tuberculosis. Materials and methods. A retrospective, selective, descriptive study which included 119 adults with pulmonary tuberculosis confirmed by the microbiological assay GeneXpert MTB/Rif wasperformed. The general group was distributed in the study group (SG) which included which 34 patients were diagnosed with 2nd type DM and control group (CG) which included 85 patients never diagnosed with DM or disturbances of glucose metabolism or DM. In 15 (44 %) patients of the SG the DM was diagnosed at the same time as TB and 19 (56 %) were diagnosed before tuberculosis with DM. The patients were registered in the period 2014—2016 in the Municipal Hospital of Pneumophtisiology of Chișinău in the Republic of Moldova. The investigational schedule included information about anamnesis, clinical examination, results of the radiolo gical and microbiological investigations performed according to the National Clinical Protocol. Statistical methods used were comparative, synthesis and discriminated analysis. Results and discussion. Ttuberculosis and diabetes represents an epidemiological challenge. In the Republic of Moldova 12.3 % of the population suffers from diabetes or reduced tolerance to glucose and almost 5 % of cases with pulmonary tuberculosis are diagnosed with diabetes. Starting with 2018 the patients with diabetes are actively annually screened for tuberculosis and the rate of patients detected by that way achieved 65 %. The research demonstrated that diabetes mellitus with disease related complications being more than 45 years old are at high risk for tuberculosis. Poor treatment outcome (death 17 %, treatment default 15 % and failure 9 %) could be explained by the comorbidity-related complications. Conclusions. Risk factor for acquiring tuberculosis in patients with diabetes mellitus is the disease itself and the related complications, as well the age more than 45 years old. More frequently the patients with diabetes were detected by active screening and had unfavorable disease outcome.