Nowadays there is an increase in nephropathy in young children, which is associated not only with environmental impacts, but also with an increase in the incidence of congenital and hereditary caused forms of diseases, an increase in the incidence of mothers, and an improvement in diagnosis. In order to analyze the frequency of congenital malformations of the urinary system in young children under the “clinical masks” of various somatic pathologies, 864 cards of inpatients that were treated in the Early Childhood Department of the Regional Children's Clinical Hospital “OKHMATDYT” during 2013 were analyzed. The authors came to the conclusion that congenital malformations of the urinary system in young children are a frequent pathology, diagnosed in 44.6% of children admitted to the To the Department of the early age for acute pyelonephritis to get 10.3% of all children who were admitted to hospital treatment. The introduction of a two-stage algorithm for the diagnosis of congenital malformations of the urinary system allows us to recognize their various “clinical masks” and timely establish a clinical diagnosis of anomalies. This approach makes it possible to conduct adequate therapy and reduce high rates of childhood morbidity and disability, and has significant medical and social effects.