BACKGROUND: Currently, inborn errors of immunity represent one of the most interesting problems in clinical immunology. The data obtained in the field of studying pathogenetic mechanisms and clinical manifestations, expanding diagnostic capabilities, including molecular genetic methods, formed the basis for revising the classification and introducing new modern treatment methods. The study of regional characteristics of inborn errors of immunity is important because it allows us to determine epidemiological indicators, clinical features of diseases and evaluate the therapy being carried out.
 AIM: To assess the effectiveness and level of continuity of medical care in the Republic of Tatarstan based on an epidemiological analysis of a group of patients diagnosed with primary immunodeficiency.
 MATERIALS AND METHODS: analysis of the register of patients living in the Republic of Tatarstan with an established diagnosis of primary immunodeficiency, observed from 1994 to 2023. A total of 240 patients were included in the study.
 RESULTS: An epidemiological analysis of inborn errors of immunity in the Republic of Tatarstan revealed an overall prevalence of 6.0 per 100,000 population, with the status "alive" ― 4.98 per 100,000 population, excluding patients with selective IgA deficiency ― 5.3 and 4.4 per 100,000 population, respectively, with a high proportion of patients over 18 years of age (53%), with the largest group of patients having defects in antibody production (42%).
 CONCLUSION: The increasing relevance of the problem of primary immunodeficiency requires special attention to the organization of medical care for patients with primary immunodeficiency, increasing continuity between specialized pediatric services and the adult network, as well as developing issues of interdisciplinary interaction.