An addition of 5% citrus pectin and 0.5% ascorbic acid to high-fat diet of guinea pigs prevented total cholesterol accumulation in blood serum and the liver. Two groups of persons were given a preparation containing a daily dose of 15 g pectin and 450 mg ascorbic acid for 6 weeks. In 21 healthy persons with mild hypercholesterolemia total serum cholesterol dropped significantly by 24 mg/100 ml (8.6%), while the concentration of high density lipoprotein cholesterol remained unchanged. In 11 hyperlipemic outpatients (type IIa, IIb and IV) total serum cholesterol dropped by 68 mg/100 ml (18.7%). The changes in triglyceridemia proved inconsistent.