This article reports on the implementation of community-based prevention of dementia among older adults in Japan. It is expected that the incidence of dementia will continue to increase as the population ages and thus care of those at risk of and with dementia is an important issue for nursing practice in the community. Community-based prevention of dementia comprises a comprehensive range of activities such as obtaining an understanding of community residents, early detection of dementia, fostering of volunteers, implementation of dementia prevention activities, provision of nursing care for older adults with dementia, as well as collaboration with local administrative institutions. We are working with a Japanese community (population of 65 years or more: about 2480 out of a total population of 10800) and in this article our activities are described. Among our activities we focus on itemizing the signs of dementia for early detection of the disease and on fostering volunteers. For early detection of dementia it is important to itemize the signs of dementia that close family members would notice in daily life. For fostering of volunteers it is necessary to enable them to develop skills to provide activities/clubs to interest the older adults and which are effective for prevention of dementia. We have started with clubs including a personal computer club, children's songs club and a picture mail club. Such activities are important strategies for a community-based intervention. The article concludes with reference to the need for verification studies to evaluate the impact of the community-based approach to the prevention of dementia outlined here which includes anticipatory education of the population concerning dementia, development of a method of early detection of dementia using a check-list and a means of secondary prevention via the activities of a group of volunteers (Ichigo Kai).