The treatment of hyperlipidemia is aimed at preventing cardiovascular disease (CVD) and coronary heart disease (CHD). As the incidence of CHD in Japan is about one-third lower and that of stroke is two-fold higher compared to Western countries, and the doses of lipid-lowering drugs used in foreign randomized controlled clinical trials (RCTs) are much higher than in general use in Japan, it remains unclear whether the results of RCTs conducted in Western countries could be extrapolated to Japanese patients. Recently, two major large-scale, prospective, RCTs in Japanese hypercholesterolmic patients, the Management of Elevated Cholesterol in the Primary Prevention of Adult Japanese (MEGA) study and the Japan EPA Lipid Intervention Study (JELIS), have been reported. Japanese epidemiological studies and Japanese clinical studies are reviewed. The evidence suggests that hypercholesterolemia, hypertriglyceridemia, and low HDL-cholesterol are strongly associated with increased CHD risk. Lipid-lowering medication shows beneficial effects even in low-risk populations; however, the data did not support that lower cholesterol is better. The safety and efficacy of hyperlipidemia treatment in Japanese patients are discussed.