In 1960, stroke mortality in Japan was the highest among industrialized countries, while CHD mortality was the lowest. Stroke mortality for men and women aged 30-69 years, however, declined by 80% during the 1965-90 years and CHD mortality also declined during the same period. Among risk factors, trends in blood pressure level and the prevalence of hypertension were very compatible with those in stroke mortality. Serum total cholesterol level has increased remarkably, however, CHD mortality has not increased. This may be explained by the decline in population blood pressure level and the prevalence of hypertension, and decreased smoking rate.