A prospective study was conducted to determine the role of intravenous pyelography (IVP) in detecting the associated urinary tract anomalies in children with urinary tract infection (UTI). A total of 143 cases with confirmed UTI all received renal sonography (RS), voiding cystourethrography (VCUG) and IVP, to evaluate for G-U tract anomaly. Associated G-U tract anomalies were noted in 67 cases (46.85%). No single method was adequate in detecting all abnormalities. Based on the anomalies detected, we proposed and compared two different conditions in which IVP was required. In condition A, in which IVP was performed when abnormal finding were found in RS or VCUG, 67 of 143 cases with UTI (46.85%, 67/143) were required to have IVP, among them 32 cases yielded positive results and 35 cases negative results. Two cases of duplex collecting system (DCS) were found only on IVP would be completely undetected under this proposed condition. However, when IVP was recommended and performed at the time of high grade VUR in VCUG or any abnormality in RS (condition B), 43 of 143 patients (30%, 43/143) with UTI were required to undergo IVP, yielding abnormal findings in 30 cases (70%, 30/43) and normal findings in 13. This would leave four cases of DCS undetected, including the 2 detectable only by IVP plus 2 more that showed low grade VUR on VCUG. However, these 4 cases would not result in progressive renal damage in long-term follow up.(ABSTRACT TRUNCATED AT 250 WORDS)