It could be a great challenge for a nephrologist to prescribe a renal replacement therapy for a critically ill, hemodynamically unstable pediatric patient. Intermittent hemodialysis and peritoneal dialysis frequently fall short of being an optimal renal replacement therapy for such a patient. Continuous hemofiltration is offering new alternatives that can deliver sufficient clearance to meet the needs of a critically ill child. High fluid intake required for total parenteral nutrition and medications can easily be fulfilled by these modalities without compromising the cardivascular system. Of these techniques, continuous veno-venous hemofiltration is superior to continuous arterio-venous hemofiltration because it delivers a consistent ultrafiltration rate dependent on pump-driven blood flow and does not require the insertion of a large-bore catheter into an artery. Thus, various modalities of hemofiltration can offer an alternative to the critically ill child with acute renal failure.