The purpose of this study was to evaluate the effects of large amounts of dietary vitamin E and butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in rabbits fed a low-cholesterol, atherogenic diet, and to seek for evidence of lipid peroxidation in the atherosclerotic lesions. Rabbits were fed a purified atherogenic diet, containing butter or the basal diet supplemented with either 1.0% of vitamin E or 0.1% each of BHA and BHT for periods up to 3 years; a negative control group was fed the basal diet with corn oil replacing butter. Aortic and coronary atherosclerosis were more frequent and extensive in rabbits fed either the basal diet or the basal diet supplemented with BHA and BHT than in rabbits fed either the basal diet supplemented with vitamin E or the negative control diet. Dietary vitamin E inhibited atherogenesis by preventing hypercholesterolemia. No evidence of lipid peroxidation was detected in the arterial lesions.