"Edentulousness is a multifactor phenomenon. While its overall prevalence is diminishing, it is increasing in older age groups. The aim of this study was to assess the prevalence of edentulousness among the elderly in two municipalities in Finland and to estimate different factors related to it. All persons born in the years 1919, 1922, 1925, 1928, 1931, 1934 and 1937 living in two municipalities (Kirkkonummi in the southern part of Finland and Lakeus in the northern part of Finland) were invited to participate in the study in 1997. The target population consisted of 1733 subjects of whom 1191 were disposed to participate in a clinical examination performed by two dentists. Of the subjects, 624 were from the southern district (Kirkkonummi) and 566 were from the northern district (Lakeus). The participation rates were 62% and 78%, respectively. The subjects answered a questionnaire comprising sociodemographical data, questions on dental and general health and health behaviour. Logistic regression analysis was used to assess the associations between edentulousness and potential associating factors. The overall prevalence of edentulousness was 37%; being 53% in the northern region and 22% in the southern region. Edentulousness was positively associated with high age [odds ratio (OR = 1.09), confidence interval (CI = 1.06-1.12)], female gender (OR = 2.06, CI = 1.43-2.94), northern place of residence (OR = 2.01, CI = 1.45-2.78), low level of education (OR = 7.09, CI = 3.18-15.81), cardiovascular diseases (OR = 1.51, CI = 1.03-2.21) and current smoking versus never smoking (OR = 1.73, CI = 1.17-2.55). Social factors were more prominently associated with edentulousness than factors related to general health."