One hundred cases of servere acute renal failure managed in the intensive care unit were analyzed to assess the value of isovolemic hemodialysis combined with interdialysis hemofiltration to control fluid balance. Forty-five patients were treated prior to the availability of this technique and 55 subsequently. There was a significant reduction in the oliguric period of survivors in the second group compared with the group treated by intermittent hemodialysis alone (p = 0.0459). The significant difference in age between survivors and deaths observed in the first group (p = 0.0027) was not demonstrated in the second group due to a reduction in the incidence of primarily cardiovascular deaths with an improvement in survival of the elderly.