Surveys were conducted in 1972 and 1990 to analyze conceptions among Finns of their own periodontal status. The interview samples, drawn to represent the Finnish population, aged 15 years and more, comprised 965 persons in 1972 and 1,006 in 1990. After excluding edentulous individuals, a total of 732 in 1972 and 853 in 1990 were accepted for the interview study. In 1990, 2% of the respondents stated that they currently had gingivitis, the percentage being highest in the youngest age group (6%). In both years there were no statistically significant differences between the age, education, and residence subgroups with regard to gingivitis: nearly 60% of those in all subgroups claimed that they had never had gingivitis. The proportions of those who had never experienced gingival bleeding were 54% in 1972 and 50% in 1990. During the first observation period the youngest age group (15-24 years) was the only one in which the increment in self-recognized gingivitis was accompanied by a higher proportion experiencing gingival bleeding. The overall low prevalence of self-recognized gingivitis is at variance with the estimated periodontal treatment need according to Finnish clinical epidemiologic data. Our results indicate that knowledge concerning periodontal disease is still poor in Finland.