Pediatric chronic kidney disease is associated with deficits in general intellectual functioning, and some evidence indicates specific deficits in memory and executive functions. Most research has focused on children with end-stage renal disease. In the current study, children with moderate as well as severe chronic kidney disease were compared with healthy controls in terms of brain activation patterns during a visual-spatial working memory task. Accuracy was similar among all groups. Reaction time was slower in patients with chronic kidney disease than in healthy controls. Patients with chronic kidney disease showed reduced activity in posterior parietal regions compared with controls, and patients with severe chronic kidney disease showed lower activation over the course of the task in numerous regions of the brain compared with controls.