Urinary tract infection (UTI) indicates the presence of a significant number of bacteria in the urine, which are habitually Gram-negative bacteria (primarily E. coli), but can also be the presence of other bacteria, fungi, and (in rare instances) other microorganisms. UTIs are second when we consider all childhood infections, just behind respiratory tract infections. The incidence of UTIs depends on the age and gender of the child, and is the highest in young children and women. The symptoms generally depend on the age of the child, and range from the non-specific in newborns and infants, to typical symptoms of urinary tract involvement in older children. Any UTI necessitates swift and correct diagnosis, while every inaugural childhood urinary infection requires additional imaging to rule out the presence of congenital anomalies, as well as adequate antibiotic treatment. Moreover, it is pivotal to pay attention to epidemiological data related to UTIs in order to detect congenital urinary abnormalities more easily and on time. Accordingly, this thesis includes a research part aimed at determining the prevalence of UTIs over three years at the Pediatric ward of the General County Hospital in Čakovec, from 2016 to 2018, with the breakdown by age and sex of the child. The subjects were children from 0 to 18 years of age, hospitalized during this period at the Department of Pediatrics of the Čakovec County Hospital, and the research method was the use of medical records stored in the written form of the Čakovec County Hospital. According to the obtained and analysed data, we can see that the girls are those who primarily suffer from urinary infections, both as a fraction of a total number of patients and within the age groups of 0-18 years. This fits into the general epidemiological situation of urinary tract and genital diseases in Croatia and globally. It is important to emphasize that the educated nurse/technician plays a large role in the care of the child due to more accurate and precise diagnostic and treatment procedures. Prevention and education also play an indispensable role, since it is known that repeated and untreated infections of the urinary system can lead to permanent damage to the kidney and renal function – especially in children.