Introduction. The peculiarity of this work is to determine the prevalence of bronchial asthma (BA) in children and the risk factors for its development in Mongolia. This country is intensively developing economically and is at the stage of transition to an industrial society, which allows assessing the impact of environmental and population changes on the frequency of BA formation. The aim of the work is to determine the prevalence and risk factors for the development of BA in children of Mongolia. Materials and methods. The prevalence of BA and data on patients aged from birth to 19 years living in Ulaanbaatar, 17 aimags and six districts of Mongolia were studied using a modified written questionnaire. To determine the prevalence of BA, we surveyed parents and 1,779 BA children patients. Information on biomedical and socio-hygienic risk factors for the development of BA in children of Mongolia was obtained after analyzing the data of a special questionnaire from 1,507 schoolchildren. All the received data are processed statistically. Results. The prevalence of BA in children of Mongolia was found to account for 11 per 1,000 children. The highest incidence of BA in children was found mainly in the northern regions of Mongolia, with a sharply continental climate and high air pollution. Among the risk factors for the formation of BA in children, the most significant are burdened heredity, smoking, unfavourable living conditions, pregnancy pathology, Breastfeeding disorders in the newborn period, irrational nutrition of the child, acute respiratory infections. In 50% of BA patients, a significant increase in eosinophils was revealed. 61.2% of patients had an increased level of IgE. Regardless of the region of residence of BA children, polyvalent pollen sensitization was the most frequent - 59.3%, food allergy - 55.5%, epidermal allergy - 38.3% of cases, household (8.3%) and fungal sensitization (5%) were rarely detected. Treatment of 89 BA children in the National Center for Maternal and Child Health hospital under the Global Initiative for Asthma strategy helped improve patients’ condition.