A total of 1784 children suffering from acute nonobstructive anuric renal failure requiring dialysis were studied in the Pediatrics Nephrology unit of Institute of Postgraduate Medicine and Research, Dhaka, Bangladesh, for the 10-year period 1981-1990. The patients were divided into two groups: Group I, the majority of the children (94.5%), presented with acute renal failure without evidence of hemolysis and were labeled as acute ischemic renal failure (AIRF), and the remaining 5.5% of the children with acute renal failure (ARF) showing features of severe hemolysis were labeled as hemolytic uremic syndrome (Group II.) The children of group I had mean age 4 (0.5-10) years, mean period of anuria 5 (2-13) days, and had mean serum creatinine 701 +/- 267.98 mumol/L. The overall mortality in this group was 89%. Children in Group II had mean age 2 (0.2-6) years, mean duration of anuria 3 (2-5) days, and mean serum creatinine level 500 +/- 100 mumol/L. The mortality rate in this group was 15%. In spite of some differences between the two groups the difference in the mortality rate between the two groups was significant (p < 0.001). It is concluded that AIRF in children bears a much poorer prognosis compared to that of ARF due to HUS.