Renal dysfunction is very common in the pediatric surgical critical care patient, with an estimated incidence of up to 35% in the PICU population. It impacts multiple other organ systems, particularly ventilation, and adds to the morbidity and mortality in children with multisystem organ dysfunction. In this article, we review the definitions and stages of renal failure in the pediatric population, identify which of these are more likely to require renal replacement therapy, and identify the indications for the different types of intervention. In addition, the complications of each form of therapy, along with management options, will be discussed. Finally, we will discuss the immediate and long-term outcomes for pediatric patients from neonates to adolescents.