['Despite the widespread availability of dialytic and intensive care unit technology, the probability of early mortality in critically ill patients with acute renal failure is still high. Previous efforts to predict the outcome in this population have been limited by small sample sizes. In addition, data obtained decades ago may not apply today owing to changes in the case mix. We have attempted to determine whether organ system failures can be used to predict prognosis.', 'The medical records of 100 consecutive intensive care unit patients with acute renal failure who required dialysis from January 1997 through December 1998 were evaluated by a blinded reviewer.', 'Of the 100 patients studied, 65 were men and 35 were women. The mean age of survivors and non-survivors was 59.4 +/- 20.3 years and 58.3 +/- 20.0 years, respectively. The overall mortality rate was 71%. There were no significant differences between survivors and non-survivors in age, gender, or indication for dialysis. The cause of death in the majority of patients was related to organ system failure, and they carried mortality rates exceeding 83% with the coexistence of four or more failed organs.'] Do organ system failures predict prognosis in critically ill patients with acute renal failure requiring dialysis?