The effect of vitamin C on cholesterolemia in a selected group of persons above 40 years of age with a seasonal deficit of ascorbic acid and with an initial level of serum cholesterolin the upper permittedlimit, or hypercholesterolemia, was studied. A nutritional situation in the examined area can be characterized by a high consumption of animal fats and sucrose, all-the-year-round deficit of vitamin A, B2 and iron and an evident seasonal deficit of vitamin C. Administration of 300 mg of ascorbic acid daily for 47 days significantly decreased the cholesterolemia. The effect of ascorbic acid was most pronounced in persons with hypercholesterolemia. In the control group not receiving ascorbic acid, the cholesterol levels showed no significant changes throughout the examined period. In the discussion it is assumed that mechanism of hypocholesterolemic effect of ascorbic acid is based on increasing catabolism of cholesterol by vitamin C.