Early identification of different categories of the risk of scarring in children with first (or follow up) urinary tract infection and/or early detection and treatment of vesicoureteral reflux are important to prevent kidney impairment. The demonstration and grading of reflux is crucial in examination and follow up of any child with urinary tract infection. Nephro-urologic radionuclide studies are able to detect vesicoureteral reflux and reflux nephropathy, such as radionuclide cystography--RNC--(both direct radionuclide voiding cystography--DRVC--and indirect radionuclide cystography-IRC), renal DMSA scintigraphy, MAG3 renal diuresis scintigraphy and DTPA renal diuresis scintigraphy. They allow to assess renal parenchyma integrity, to detect pyelonephritic scars, to evaluate the different aspects of urinary tract function and to measure absolute and relative function after intravenous injection of radiopharmaceuticals. The procedure, image acquisition and processing and the diagnostic relevance of all aforesaid nephro-urologic radionuclide studies are illustrated.