Objective: To study main clinical and laboratory peculiarities of the course of urinary tract disease among children aged from newborns to 3 years old.Methods: Research design is a prospective controlled clinical research. 102 (60.71±3.77 %) children having urinary tract infection without accompanying abnormalities of the urinary system development were included in the first group. 66 (39.29±3.77 %) children having infection of the urinary tract amid congenital kidney defect.Results: Comparative evaluation of the results of complex examination of both groups showed that urinary tract infection is characterized by intoxication, pain and dysuric syndroms. The presence of accompanying kidneys and urinary tract abnormality development defined the latent course of the disease in every second child (59.09%) and supports the early development of renal infection (during first six months after birth).Conclusions: It’s necessary to conduct the search of diagnostics markers and predictors of the infection of the urinary tract among children of the first years of life, especially if there is an abnormality of the organs of urinary system.