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. The term “uncomplicated” usually reflects UTIs in premenopausal, non-pregnant women with no known anatomical or functional urological abnormalities or other comorbidities. Some authors advocate thinking about UTIs in postmenopausal women or women with well-controlled DM without urological sequelae also to be “uncomplicated”.