Sixteen patients with hyperuricemic acute renal failure were treated or had their cases reviewed. Eleven of the patients were treated with dialysis and five were treated conservatively. The prognosis is excellent, as all survived acute renal failure, and renal function rapidly returned to normal after lowering of the uric acid level with dialysis. Dehydration and ureteral obstruction were rare causes of acute renal failure, and prophylactic allopurinol and potent diuretics were not always successful in preventing or aborting it. A high phosphorus-to-uric-acid ratio occurred where hyperuricemic acute renal failure occurred as a complication of chemotherapy with precipitous falls in peripheral white blood cell counts. Hemodialysis is the treatment of choice, being 10 to 20 times more efficient than peritoneal dialysis in the removal of uric acid, and there is no disequilibrium even with rapid hemodialysis.