Effect of natural zeolites as a food supplement on renal function and plasma in rats with acute renal failure has been studied. Renal function was determined using urine collected from rats placed in metabolic cages in basal conditions and following intragastric intake of 5% water load. Samples of blood were collected in anesthetized animals by punction of v. cava inferior. The parameters of urine and plasma such as concentration of creatinine, urea, sodium, potassium and osmolality were measured. In rats with acute renal failure (ARF) creatinine and urea concentration in plasma increased from 2,1 ± 0,1 to 8,1 ± 1,1 mg% and from 39,2 ± 4,4 to 322,8 ± 65,0 mg% respectively GFR and tubular fluid reabsorption decreased significantly. In 3 days following zeolites intake there was significant decrease of creatinine and urea concentration in plasma of ARF rats compare to ARF animals on regular diet. Zeolites diet also affected the renal processes that reflected in increase of GFR and tubular fluid reabsorpion as well elevation of diuresis. Thus, zeolites as diet supplement can be used to normalize renal function and water-salt homeostasis in rats with experimental model of acute renal failure.