In a series of 104 pediatric patients, the diagnostic accuracy of the camera renal scan with iodohippurate sodium I 131 with simultaneous renogram (camera renogram) was compared with intravenous pyelography. There was correlation between the two tests as to normal (21 cases) or abnormal (53 cases) in 74 patients. In seven patients, the camera renogram detected abnormality confirmed by voiding cystourethrograms or other studies when the intravenous pyelogram was interpreted as within normal limits. Comparison of intravenous pyelogram was not obtained in five patients due to previous allergic reaction to intravenous pyelographic media and in two patients due to azotemia. Nineteen patients showed a normal camera renogram when they were studied after one episode of urinary tract infection. No renal disease has subsequently been found in this group. The accuracy and safety of this isotope procedure demonstrated in this preliminary series suggests its use as the initial screening procedure for early detection of urologic problems.