BACKGROUND: Previous epidemiological data for pediatric patients with acute renal failure (ARF) predate current intensive care unit (ICU) technology and practice, and do not reflect newer disease therapies for bone marrow, hepatic, and cardiac transplantation and congenital heart disease surgery. METHODS: We conducted a retrospective review of 254 ARF episodes in 248 children discharged from a tertiary referral center, Texas Children's Hospital (Houston, TX), between January 1998 and June 2001 to update current pediatric ARF epidemiological characteristics. RESULTS: The most common causes of ARF were renal ischemia (21%), nephrotoxic medications (16%), and sepsis (11%). Primary renal diseases accounted for only 17 cases (7%), and hemolytic uremic syndrome accounted for only 3 cases. Overall ARF survival for the entire cohort was 176 of 254 patients (70%), whereas 110 of 185 patients (60%) requiring ICU admission and 43 of 77 patients (56%) receiving renal replacement therapy survived. CONCLUSION: These current pediatric ARF data show that pediatric ARF epidemiological characteristics have changed from primary renal disease to renal involvement secondary to other systemic illness. Longitudinal data from this cohort are underway to determine the long-term sequelae of pediatric ARF.