Plant sterols are natural dietary components whose lowering effect on serum cholesterol level has been well documented. The purpose of this study was to determine the effects of plant-sterol-supplemented processed rice on serum of cholesterol level. In the determination, a double-blind, placebo-controlled study was conducted using a 3-group parallel protocol. The subjects comprised 33 healthy Japanese males and females with a total cholesterol level of 234. 6± 24.6 (mean±SD, mg/ml). They were given a daily ration of rice balls prepared from plant-sterol-supplemented rice containing 1.46 and 2.25 g of plant sterol for 4 weeks. Serum total cholesterol was reduced by 4.6% in the 2.25 g/day plant-sterol (as β-sitosterol of about 968 mg/day) group ( p <0.05). As for LDL cholesterol level, such reduction was observed in 4.3%. In all the groups, no significant change in the level of HDL-cholesterol, triacylglycerol, RLP-cholesterol, VLD-lipoprotein, LD-lipoprotein or other kinds of apolipoprtein and biochemical parameters. In addition, no remarkable abnormality was observed in the subjective and objective examination of what symptoms. These results indicate that plant-sterol-supplemented processed rice is useful in supporting healthy eating habits for reducing serum total cholesterol level.