Aim of the study: is an epidemiological analysis of the incidence of HIV infection in the Republic of Mari El for the period from 2014 to 2023. The study is aimed at identifying the dynamics of morbidity, analysing the transmis-sion routes and assessing the effectiveness of preventive measures. Materials and methods: the study used data from the report of Rospotrebnadzor ‘On the state of sanitary and epi-demiological well-being of the population of the Republic of Mari El in 2023’ and publications from the CyberLenin-ka portal. Retrospective analysis was chosen as the research method, which allowed to assess changes in the inci-dence of HIV infection for the specified period. Results of the study. The analysis showed that there was a decrease in incidence in 2014 and 2015, but from 2015 to 2018, the frequency of case registrations started to increase. Between 2018 and 2022, there was a decrease in the number of cases, but in 2023, the number of registrations increased again to 31.2 per 100,000 population. The highest incidence was recorded in the cities of Volzhsk and Yoshkar-Ola, as well as in Volzhsky and Medvedevsky districts. In the first five months of 2023, 99,564 people were examined and 86 new cases were detected, which is significantly higher than in the same period of 2022. Conclusion. The situation with HIV incidence in the Republic of Mari El remains unstable and requires active in-tervention by health authorities. Despite some successes in prevention, the increase in the number of new cases in 2023 highlights the need to strengthen education programmes and the availability of antiretroviral therapy. Sexual transmission remains the leading route of transmission, which requires an emphasis on safe behaviour. Sustained at-tention and action can help reduce the incidence and improve the quality of life of people living with HIV.