BACKGROUND: Over the past 40 years, the incidence of obesity in children aged 5 to 19 has increased tenfold. Due to the growth of childhood obesity as a socially significant chronic non-communicable disease, since 2014 the World Health Organization has announced the need to monitor the physical development of children and adolescents in order to develop actual methods to decrease the prevalence of childhood obesity and monitoring their implementation.AIM: To determine the actual prevalence of childhood obesity in Tyumen region among children and adolescents from 3 to 18 years.MATERIALS AND METHODS: A one-time continuous study of 5,130 students of preschool and school institutions of Tyumen region from 3 to 18 years old was conducted as part of preventive examinations of underage children. The study included measurement of height, body weight, determination of body mass index (BMI) and calculation of SDS (SDS — standard deviation score) BMI for a certain age and gender. Assessment of physical development was carried out according to WHO criteria (2005, 2007).RESULTS: The prevalence of overweight and obesity in Tyumen region was 15.2% and 8.4%, accordingly, among boys over weight and obesity were diagnosed in 13.5% of cases, among girls — in 10.2%. While analyzing the periods of childhood it was found that obesity is 1.4 and 2.1 times more common among boys than among girls at preschool and primary school age, accordingly, p=0,027 and p<0,001. In the clinical structure of obesity, grade I obesity was significantly more often observed — 55.5%, p=0,027.CONCLUSION: The actual prevalence of childhood obesity in the Tyumen region is 8.4%. In general, among girls, obesity was registered in 5.4% of cases, and among boys it was twice as much — 10.7%. SDS BMI more them +3,1 are more often diagnosed in preschool and primary school age.