Summary: Urinary tract infections (UTI) are the most common bacterial infection in the pediatric population and pose a serious diagnostic and therapeutic challenge for physicians. It is mainly related to uncharacteristic clinical symptoms in the youngest patients and high recurrence rate. Among many risk factors for the occurrence of UTI, the most important are congenital defects with urinary outflow obstruction in younger children, and in older children constipation and lower urinary tract dysfunction. The pathogen’s virulence is important too. Generally, the prognosis is good, but in some cases upper urinary tract infection may lead to serious complications, including death. These particular groups include pregnant adolescents, children infected with Pseudomonas aeruginosa, and patients with neurogenic bladder; they require a different diagnostic and therapeutic approach. This paper discusses in detail the problems of these patients and the principles of management in the light of current recommendations of scientific societies, especially the Polish Society of Pediatric Nephrology.