Urinary tract infection (UTI) is one of the major bacterial disease of children that causes morbidity andinconvenience to man patients were related to recurrent vesicoureteral reflux. Radiological examinations of the 72patients of urinary tract infection (UTI) who were visited to Seoul Paik Hospital from Jan, 1st 1986 to Jul. 30th1989, were analysed in this study. US was used as an initial study in all patients who showed acute stage of UTIand followed by IVP, VCUG, 99mTc-DMSA scan for vesicoureteral reflux of renal scarring. If US showed obstructinglesion, no further study was performed. The results were as follows: 1. US is valuable as a screening procedureduring the first UTI in congenital abnormalities and in particular obstructive lesions that require surgery. 2. Anormal US in a child older than 5 or 6 years is meaningful as an investigation in the group of the firstdocumented UTI uncomplicated. 3. Vesicoureteral reflux, a major factor leading to parenchymal damage in youngchildren can not be detected reliably by US. If the US is suggestive of vesicoureteral reflux, this should beconfirmed by VCUG and 99mTc-DMSA scan for renal scarring. If the US is normal or eqivocal in recurrent infectionand unexplained persistent clincial findings, this should be followed by VCUG and 99mTc-DMSA scan.