The pathology of the processus vaginalis of the peritoneum (inguinal hernia, hydrocele testis) is quite widespread among the pediatric population, both in our country and throughout the whole world. More than 99% of inguinal hernias in children are oblique, right-sided localization is more than 3 times more common than left-sided. High interest of scientists in the study of the pathology of the processus vaginalis of the peritoneum is caused by data on the appearance of infertility as a complication of inguinal hernias and dropsy of the testicles. In the structure of the causes of this situation, 30% belongs to the male factor, and this percentage has a constant tendency to increase. This became the reason for an additional study of the mathematical component of the prevalence of the pathology of the processus vaginalis of the peritoneum among the children’s population. Purpose - to create a mathematical model of the prevalence of pathology of the processus vaginalis of the peritoneum depending on age and gender among the children’s population. Materials and methods. 205 patients under the age of 18 who underwent surgical correction of the pathology of non-obliterated processus vaginalis of the peritoneum (inguinal hernia, hydrocele testis) took part in the conducted scientific study. For mathematical modeling, software built into Microsoft Excel was used (Trend line, polynomial regression equation of the 4th degree). Results. In the course of mathematical modeling, characteristic features were identified: they occur both in the female part of the pediatric population and in the male, similar fluctuations are noted in the general pediatric population, namely periods of increase in the frequency of pathology of the vaginal peritoneum, which alternate with periods of its decline. a rapid increase in the frequency of pathology of the vaginal peritoneum, and, accordingly, their surgical correction, in children under 3-4 years of age, followed by a decrease in frequency by the age of 11-13 years. The following slight increase in the frequency of diagnosis of pathology of the vaginal peritoneum and its surgical treatment was detected by the age of 15-16 years, followed by a gradual decrease in the frequency by the age of 18 years Conclusions. Therefore, there are two mathematically confirmed peaks of growth in the frequency of detection of the pathology of the processus vaginalis of the peritoneum, which fall on the age of verticalization of the child and the age of “specialized” loads. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors.