The effects of dietary oil from ordinary miso and miso augmented with Perilla frutescens seeds (blended miso) on serum and hepatic lipids were investigated in rats fed diets containing 5 % lard and 5% miso oil. The n-3/n-6 ratio in fatty acid compositions of oil extracted from ordinary miso and blended miso were 0.11 and 0.70, respectively. The concentrations of serum cholesterol in rats fed diets with miso oil for 14 days decreased in order from control>ordinary miso>blended miso. In particular, total cholesterol values showed significant differences between the control diet, the ordinary miso diet, and the blended miso diet. Free-cholesterol values were also significantly different between the control diet and the ordinary miso diet, and the control diet and blended miso diet. We speculated that the potent hypocholesterolemic activity in the ordinary miso and blended miso oils significantly affected the n-3/n-6 ratio and the polyunsaturated fatty acid/saturated fatty acid ratios. The concentrations of serum triglyceride increased in order from the control diet