The effect of repeated courses of enterosorption upon the mean and maximal lifespan and some functional and metabolic indices was determined in 28-month-old Wistar rats. Significant increase of mean and maximal lifespan of old rats was noted at certain regimens of enterosorption. The experimental animals demonstrated less marked age-related structural and ultrastructural changes in the liver, kidneys, myocardium, intestines, pancreas, as compared with control animals. Enterosorption leads to a reduction of pentobarbital-induced sleep, decrease of content of cytochrome P-450, blood cholesterol and triglycerides, cardiac and cerebral tissue cholesterol, total lipids, liver cholesterol and triglycerides. Enterosorption was found to increase the RNA and protein biosynthesis in the liver, kidneys and adrenals of old animals.