OBJECTIVE: To compare resource utilization and outcomes between cohorts of pediatric and adult intensive care unit (ICU) patients from a single institution. DESIGN: Prospective, observational cohort study. SETTING: A large, urban, tertiary care medical center. PATIENTS: A total of 780 patients consecutively admitted to the pediatric ICU, adult medical ICU, and adult surgical ICU. MEASUREMENTS AND MAIN RESULTS: ICU, hospital and 6-month survivals and hospital costs from index ICU admission. Predicted mortality by Pediatric Risk of Mortality III and Acute Physiology and Chronic Health Evaluation II. Health status at 6 months from index ICU admission. Pediatric patients had lower ICU (7.8% vs. 13.7%; p =.01), hospital (10.1% vs. 16.9%; p =.009), and 6-month (16.2% vs. 29.2%; p <.001) mortalities compared with adult patients. Adult patients had significantly lower probability of survival for 6 months from initial ICU admission compared with pediatric patients. The difference in survival was primarily accounted for by adult and pediatric medical patients. No differences could be observed between pediatric and adult ICU patients for mean hospital costs ($33,316 +/- $48,467 vs. $32,877 +/- $46,411; p =.92). Pediatric and adult patients incurred increasing costs with increasing risks of mortality. More than 50% of pediatric patients had a risk of mortality <0.5% compared with 1.2% of adult patients, but there was no difference in the mean use of ICU-specific interventions. CONCLUSIONS: Pediatric critical care patients have better short-term and longer-term survival compared with adult patients. The difference in survival is accounted for by the lower survival of adult medical patients. Despite the survival differences, pediatric and adult ICU patients incur similar hospital costs, and the proportions of patients who receive active ICU interventions are similar.