With the rapid aging of the population in Korea, the number of older people with dementia is projected to increase, forecasting an epidemic of dementia. Recent trends in dementia in several western countries, however, depict a gradual decline in prevalence and incidence. This decrease has been attributed to an improvement in education and living environments, engagement in healthy behaviors, and reduction in the prevalence of vascular risk factors. In Korea, however, trends in modifiable risk factors do not favor an optimistic outlook due to the continuous increase in the prevalence of hypertension, diabetes mellitus, and obesity. Given these observations, there is much to be gained through the promotion of healthy lifestyles. Moreover, public health resources need to be directed toward the provision of health promotion and preventive services, control and management of vascular risk factors, and improvement in the standard of living. Nationwide initiatives to develop and implement policies and strategies to protect cognitive health throughout the lifespan should be considered a public health priority.