The purpose of the study: The purpose of this work was to study the prevalence of bronchial asthma and chronic bronchitis in adolescents, depending on the factors of the ecosystem and climatic zones in the Republic of Dagestan according to the data of the incidence and morbidity. Material and methods of research: We analyzed statistical data on the incidence and incidence of bronchial asthma and chronic bronchitis among adolescents aged 14–18 years for 5 years (2018–2022) in the lowland, mountainous and foothill zones of the Republic of Dagestan according to the Ministry of Health of the Republic of Dagestan. Previously, similar studies have not been conducted in this age group. Results and their discussion: From these data it can be seen that, firstly, in the republic as a whole, the increase in the incidence of bronchial astma in adolescents amounted to 124.4 % (from 0.86 to 1.93 per 1000 population); secondly, a steady increase in the incidence of bronchial astma is observed in rural areas (228 % vs. 53.8 % in cities), thirdly, the incidence has its own characteristics depending on the height of residence above sea level (mountains – more than 1000 m, foothills – 500–1000 m, plain – less than 500 m). A comparative assessment of the data on the prevalence of asthma in cities and rural areas revealed the following patterns: in general, adolescents in villages are almost 2 times less likely to suffer from bronchial asthma than in the city (summary figures for 5 years per 1000 population – in rural areas – 0.96, in urban areas – 1.78). Although the increase in the number of adolescents with bronchial asthma was also noted among urban residents (by 53.8 %), but among rural adolescents the increase in 5 years exceeded 4 times and amounted to 228 % (0.57 in 2018 and 1.86 in 2022). The heterogeneity of the incidence of chronic bronchitis by year was noted in all climatic zones. In the mountainous climatic zone, the incidence in 2018 was 14.7 per 1000, in 2019 there was a slight decrease (10.5), and in subsequent years there was a gradual increase and by 2022 it reached 19.3 per 1000 population. There were no large differences in morbidity in the foothill zone, although in 2022 it decreased to 3.2 compared to other years (6.4 in 2018, 7.2 in 2019, 5.3 in 2020 and 7.0 in 2021). The same situation was observed in the lowland zone, although in general, the incidence rate in this climatic zone increased from 5.5 in 2018 to 7.3 in 2022, with insignificant differences in 2019 (8,6) and 2020 (4,4). Conclusions: Bronchial asthma is a common disease among adolescents in the Republic of Dagestan and there is its close dependence on both climatic zones and ecosystem factors. When comparing the data on the prevalence of bronchial asthma in urban and rural areas, the following patterns were revealed: in general, adolescents in villages are almost 2 times less likely to suffer from bronchial asthma than in the city. Although the increase in the number of adolescents with AD was also noted among urban residents (by 53.8 %), but among rural adolescents the increase in 5 years exceeded 4 times and amounted to 228 %. Regarding chronic bronchitis, heterogeneity of morbidity by year was noted in all climatic zones. In the mountainous and lowland zones, there was an uneven increase in the incidence of chronic bronchitis over the years, and in the foothill zone there was a downward trend. Such differences in morbidity rates can only be explained by the lack of a unified approach to the nomenclature and diagnosis of chronic bronchitis in various medical institutions of the republic.