A cardiovascular epidemiologic study was performed in three different areas in Okayama prefecture in 1982. The incidence of hypertension in Sakuto-cho was higher than in the other two areas. However, the incidence was less than in previous studies. Conversely, the incidence of ischemic heart disease was higher in Sanyo-cho. In the group of essential hypertensions, IHD and obesity, HDL-cholesterol was low, and total cholesterol, triglyceride and LDL-cholesterol were high compared with the normal group. In women, with or without disease, total cholesterol and LDL-cholesterol were high compared with men, while the HDL-cholesterol/total-cholesterol ratio was low. Along with an increase in age, HDL-cholesterol decreased, and total cholesterol and LDL-cholesterol increased in men and women. HDL-cholesterol in Sakuto-cho was significantly high, and total cholesterol and LDL-cholesterol in Osafune-cho and Sanyo-cho were low.