Intravenous urography (IU) was performed in 489 patients aged 0-9 years during 1980-1983. A total of 35 (7.2%), 19 (13.1%) boys and 16 (4.7%) girls had pathological changes at IU. Of these, 11 boys and 5 girls had findings with therapeutic consequences. We have analysed the results of IU and voiding cystoureterography (VC) in 62 patients and show that a normal IU does not exclude vesicoureteral reflux into the renal pelvis. By performing only VC hydronephrosis, pyelonephritic scarring and anomalies may be missed.