Purpose: Acute kidney injury in the pediatric intensive care unit (PICU) is associated with significant morbidity, with continued mortality greater than 50%. Previous studies have described an association between percentage of fluid overload (%FO) less than 20% and improved survival. We reviewed our continuous renal replacement therapy (CRRT) experience to evaluate for factors associated with mortality as well as secondary outcomes. Materials and Methods: This is a retrospective chart review of pediatric CRRT intensive care unit patients from January 2000 to September 2005. Results: Seventy-six admissions required CRRT during the study period. Overall survival was 55.3%. Median patient age was 5.8 years (range, 0-18.9). Median %FO at the time of CRRT initiation was 7.3% in survivors vs 22.3% in nonsurvivors (P = .0001). Presence of sepsis was significantly associated with mortality (P = .0001). All nonsurvivors had multiple organ dysfunction syndrome (MODS); only 69% of survivors had MODS (P = .0003). For survivors, there was a significant relationship between %FO and time to renal recovery (P = .0038). Greater %FO was also associated with significantly prolonged days of mechanical ventilation (P = .0180), PICU stay (P = .0425), and duration of hospitalization (P = .0123). Conclusions: For patients with acute kidney injury who require CRRT, the presence of sepsis, MODS, and FO greater than 20% at the time of CRRT initiation are significantly associated with higher mortality. In addition, we report that duration of mechanical ventilation, PICU stay, hospitalization, and time to renal recovery were all significantly prolonged for survivors who had FO greater than 20%. © 2009 Elsevier Inc. All rights reserved.