This study examined the relationship between dental care and dental health status in institutionalized elderly people in Japan through a 6-year prospective cohort study. All the 719 subjects received both baseline and follow-up surveys. The uptake of dental care was examined at the follow-up survey. We examined the relationship between baseline variables and the provision of dental care, and the relationship between dental care and change of oral health status. About 47% of the subjects and about 60% of the baseline dentate subjects received some dental treatment during the 6-year follow-up period. The subjects who were in better systemic and dental health at baseline used dental services frequently. The number of teeth needing extraction decreased in the subjects who received dental treatment, and increased in the untreated subjects. Denture status was better in the treated subjects than in the untreated subjects. Dental care appears to be an important factor in maintaining a healthy oral status for the institutionalized elderly.