In 26 patients with chronic renal failure undergoing hemodialysis, use was made of an acetate solution (40 mmol/l) and in 7 patients, of a bicarbonate solution (35 mmol/l). The control group was made up of 20 healthy volunteers. In addition to better tolerance, the bicarbonate dialysis favoured adequate correction of acid-base balance, normalization of hypercholesterolemia, lowering of the rate of protein degradation. Among patients on the acetate dialysis, subgroups with normal (9 persons) and delayed (17 persons) acetate utilization were distinguished. A close relationship was discovered between blood acetate concentration before procedure and the rate of urea generation (r = +0.79, p less than 0.05). It is assumed that the acetate dialysis intolerance is determined by protein hypercatabolism under the conditions of delayed utilization of acetate by the peripheral tissues.