The aim of this review is to determine the diagnostic accuracy of tests for detecting urinary tract infection (UTI) in children under 5 years of age and to evaluate the effectiveness of tests used to investigate further children with confirmed UTI. Also, to evaluate the effectiveness of following up children with UTI and the cost-effectiveness of diagnostic and imaging tests for the diagnosis and follow-up of UTI in children under 5. An additional objective was to develop a preliminary diagnostic algorithm for healthcare professionals.