Urinary tract infections (UTIs) are a common cause of morbidity in children. The distinction between upper and lower tract UTI is clinically difficult but important, as permanent renal damage can occur when the UTI involves the kidneys. Children with a history of UTI need investigated promptly and thoroughly. The goal of imaging in UTI is to aid in the diagnosis of acute pyelonephritis, to identify those children who are at high risk of developing permanent renal damage, and to confirm and monitor the presence of renal scarring. This article reviews the role of radiology in each of these aims.