The effects of palm oil supplementation (5%) to a cholesterol-based (5%) diet on lipid peroxidation, and on glutathione peroxidase activity in rat's liver were examined. The rate of lipid peroxidation in the liver was determined in vitro by the thiobarbituric acid (TBA) test, and by conjugated diene measurement. Palm oil supplementation significantly reduced (p<0.05) the rate of lipid peroxidation in the liver of rats fed 5% cholesterol, compared to the rate observed in the liver of rats fed 5% cholesterol diet without palm oil. On the other hand glutathione peroxidase activity was significantly increased (p<0.05) in the liver of rats fed palm oil supplemented diet compared with those fed cholesterol diet without palm oil. The study suggests that palm oil feeding could be a veritable nutritional tool in the prevention of lipid-induced oxidative damage as usually observed in atheromatous plaque.