Objective To compare the effects of high-monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) against the metabolic disorders elicited by a high-cholesterol diet (HC) in rats. Methods Using in vivo dietary manipulation, rats were fed with different diets containing 4% soybean oil (cholesterol free diet) and 1% HC containing 12% olive oil (HC + OO) enriched with MUFA and 12% sunflower oil (HC + SO) enriched with PUFA for 60 d. Serum lipid levels and hepatic steatosis were evaluated after the treatment period. Results Comparatively, rats treated with HC + OO diet experienced a decrease in the serum LDL-C, VLDL-C and CT levels compared to those fed with HC + SO diet (P < 0.05). Otherwise, HC + OO provoked significant microvesicular steatosis situated in the hepatic acinar zone 1. Conclusions HC + OO diet has high absorption velocity in the acinar zone 1 of liver compared to the HC + SO diet. Based on this, the reduction of the LDL-C, VLDL-C and CT serum levels in the animals treated with HC + OO diet may have been caused by the delay in the FA release to the blood.