The current Ukrainian population health status is characterized as critical. The article has analyzed the results of the sociological sampling among the children aged 0-14 and 15-17 years inclusively, as well as prevalence of diseases of the digestive system; the medical and social significance of influence of this pathology on the most substantial periods of growth and development of a child and duodenal ulcer incidence rate among children. Objective: to study the prevalence of the digestive system diseases, including duodenal ulcer among school-aged children in Ukraine. Materials and methods: sociological and process analysis methods were used. Results and discussion. The article presents the sociological sampling project scheme. The research comprised 597 children who live in cities and in rural area. We have presented the results of the sociological sampling of the first group of the children with the digestive system diseases, namely: 198 children, including 102 children living in cities and 96 – in rural area. According to the research program, we studied and analyzed the results of sociological sampling among the children in the Kyiv City and Kyiv Region and gave the recommendations on health improvement to the children with duodenal ulcer and their parents. Conclusion. The results of surveying the school-aged children with the digestive system diseases and other population categories, the study of their opinion will give an opportunity to prepare the further actions plan to prevent these diseases.