Bacterial urinary tract infections (UTI) are common in young children. The presence of fever is considered to be a marker of renal parenchymal involvement. Renal damage during the acute phase of infection may lead to scarring, yet the role that scarring plays in the appearance of chronic kidney failure is unknown. It is also unclear what influence scars have on the natural course of kidney function, especially in children with renal hypodysplasia, with or without vesicoureteral reflux (VUR). Renal hypodysplasia is the most common cause for dialysis and transplantation in the pediatric population.