Relevance. Early caries is one of the most prevalent childhood diseases worldwide. Up to 32% of three-year-olds have tooth decay, the prevalence of caries in 6-7-year-old children in different cities of Russia increases to 65%, while 55.7% of children have caries of permanent teeth. In order to improve the quality of dental care, it is necessary to receive information about the prevalence and intensity of dental diseases, taking into account medical geography. Purpose – to assess caries and fluorosis incidence rate in primary teeth, to determine the hygiene index and the level of dental care for children under seven years old living in regions with different fluoride concentrations in drinking water.Materials and methods. The study conducted dental examinations of 150 children living in the South-Eastern Administrative District of Moscow aged 1 to 6 years and of 200 children living in Krasnogorsk aged 1 to 6 years. The study included the patients based on the developed inclusion criteria and informed voluntary parent consent. We entered the data into the registration card, which noted the dental formula, the prevalence and intensity of caries, the hygiene index according to Fedorov-Volodkina, the level of dental care according to P.A. Leus (1987).Results. Children living in an area with a low fluoride concentration in drinking water show the first signs of caries by the first year of age, then there is a significant increase, observed in the group of 3and 6-year-olds. The prevalence of caries in 1-year-old children living in an endemic focus of fluorosis is almost two times lower than in children living in an area with a reduced content of fluorides in drinking water, in 3-4-year-old children – 1.5 times lower, and in 5-6-year-old children 2 times lower. Along with this, 16-year-old children living in the focus of endemic fluorosis, Krasnogorsk, Moscow region, revealed fluorosis of primary teeth with a prevalence of 27%.Conclusions. The results indicates the need to increase the frequency and quality of patient education and increase the level of dental care.