Aim – to analyze the main aspects of tick varieties, the degree of their infection and to study the features of the clinical manifestation of tick-borne borreliosis in the Penza region. Material and methods. Data from 1,570 ticks delivered to the Center for Hygiene and Epidemiology in the Penza Region, 56 medical records of patients receiving medical care from infectious disease doctor, who sought consultation with an infectious disease specialist regarding a tick bite. Results. Among the 1,570 ticks examined, 338 individuals (21.53%) were infected, 71.89% of cases were detected in the city of Penza and the Penza district, 28.11%, in other districts. 20 administrative districts are endemic. Analysis of the sex structure of the infected ticks examined showed that female ticks accounted for 276 individuals (81.66%), nymphs, for 61 individuals (18.05%), and male ticks, for one individual (0.3%). In 2023, we analyzed 56 patients receiving medical care from infectious disease doctors. Using the PCR, 10 patients were found to have Borrelia burgdorferi s.l. DNA, 2 patients, A. phagocytophilum DNA, 1 patient, E. muris/chaffeensis DNA. ELISA was performed in 22 patients (39.29%); IgM were detected in 37.5% of examined, IgG were detected in 62.5% of patients. Conclusion. The dominant tick-borne infection in the Penza region is tick-borne borreliosis, the main carrier is Ixodes ricinus (98.82%). Among the infected ticks, females predominate (81.66%). The main area of infected ticks is Penza with 48.22%. Among the infected ticks, Borrelia burgdorferi s.l. DNA prevails (98.82%).