The periodontal status of a Scottish prehistoric population was studied. No individual over the age of 10 yr had an entirely healthy periodontium. Gingivitis was the most widespread disease state in the adolescent and younger age groups. The progression towards periodontitis was at a constant rate and mirrored modern epidemiological studies. A small proportion of individuals proved to be either more susceptible or resistant to periodontal disease. There was no evidence of periodontal disease prevalence being higher than that of modern societies with access to dental treatment. Much can be learnt regarding the natural history of periodontal disease by the study of archaeological material.