We surveyed the frequency distribution of dental caries prevalence in 796 elementary school children and found theoretical distributions adequate to analyze caries prevalence data in Japanese children. The frequency distributions of dental caries prevalence in the first- and the second-grade children usually had a Poisson distribution for the years 1995 to 2007, while third-, fourth-, fifth- and sixth-grade children changed from a quasi-normal distribution to a Poisson distribution between 1995 and 2007. The Survey of Dental Disease for 2005 had a frequency distribution of caries prevalence with a Poisson distribution in 6, 7 and 10 year-old children. These findings suggest that the Poisson distribution is appropriate as a theoretical distribution for analysis of dental caries prevalence data in Japanese children, and that it can be used as a basis for making decisions on oral health activities.