Febrile urinary tract infection (UTI) is one of the most common bacterial illnesses in children. As febrile UTI may lead to acute renal parenchymal damage, possible permanent renal scarring decreased renal function, and endstage renal disease, early diagnosis, and treatment are important. Urinary tract infections (UTIs) are among the most commonly encountered bacterial illnesses. In adults, UTIs can be classified into acute uncomplicated cystitis, acute uncomplicated pyelonephritis, complicated UTI, and acute complicated pyelonephritis. For men, several categories of prostatitis are distinguished. According to the above-mentioned classifications, febrile UTI includes complicated UTI with fever, acute prostatitis, acute (un-complicated pyelonephritis, and, as has been suggested, the urosepsis syndrome. The optimal treatment duration of febrile UTI has not been established yet, but current strategies recommend antimicrobial treatment for about 14 days in most patients. With the paucity of new antimicrobial classes in development, it is increasingly important to develop strategies to maintain or even increase the effectiveness of the available agents.