The cholesterol-lowering and anti-atherogenic effects of non-hydrogenated (FCP-3P1 containing 69% beta-sitosterol, 16% sitostanol, and 13% campesterol) and hydrogenated (FCP-3P2 containing 77% sitostanol, 11% campestanol, and 8% beta-sitosterol) Phytrol trade mark have been compared in apo E-deficient mice. After consumption of 0.2% (w/w) cholesterol-enriched diet, the elevated plasma cholesterol levels observed in controls was significantly reduced by the addition of either 0.5%, 1% or 2% FCP-3P1 or FCP-3P2 at week 4. Compared to controls, the treatment of 0.5%, 1%, and 2% FCP-3P1 in the diet resulted in reduction in cholesterol concentrations by 33.6%, 46.8% and 52.4% at week 8, respectively, whereas the reduction in plasma cholesterol levels by 0.5%, 1%, and 2% FCP-3P2 was only 20.5%, 38.7% and 31.7% indicating lower cholesterol-lowering effect of the hydrogenated phytosterols at all doses as compared with non-hydrogenated phytosterols (FCP-3P1). By contrast, FCP-3P1 and FCP-3P2 showed comparable non-significant anti-atherogenic properties in treated animals after 14-week treatment. 0.5%, 1%, and 2% FCP-3P1 treated apo E-deficient mice had a mean aortic lesion area that was smaller than controls although the reduction of atherosclerotic lesions did not reach the statistical significance. In conclusion, this study did not show statistically significant differences between hydrogenated and non-hydrogenated plant sterols with regard to their cholesterol-lowering and anti-atherosclerotic properties in apo E-KO mice.