Introduction. In the Republic of Bashkortostan, the prevalence of rare (orphan) diseases remains an urgent medical and social problem. In this regard, in order to improve medical and social care for patients with orphan diseases, new methods for registering patients are being developed and implemented, registration criteria are being revised, modern methods of diagnosis and treatment, including high-tech ones, are being introduced. Goal. The purpose of our study is to analyze the regional register of people suffering from life-threatening chronic progressive rare (orphan) diseases, leading to a reduction in the life expectancy of citizens or their disability in the Republic of Bashkortostan for 2018-2021. Materials and methods. The work used data from the regional register of the Republic of Bashkortostan and presented the medical and statistical characteristics of patients with orphan diseases in the region for 2018-2021. Results and discussion. As of 01.01.2022 in the regional register of the Republic of Bashkortostan there were 510 patients suffering from orphan diseases. Medical and statistical analysis of the regional register data showed that in 2021. compared to 2018 there was an increase in the prevalence of orphan diseases: from 10.0 cases per 100 thousand of the population to 12.7 cases per 100 thousand of the population (p 0.05). However, the prevalence of orphan diseases among the rural population is higher than among the urban population (p ed: from 10.0 cases to 12.7 cases per 100,000 populations (by 21.2%). The increase in the prevalence rate is explained by the fact that in recent years more attention has been paid to the early diagnosis of orphan diseases, the criteria for entering patients into the official register, methods of treatment and providing patients with orphan diseases with drugs.