Objective The purpose of this study was to evaluate the prevalence and severity of periodontitis in men of 65+ years and identify demographic and lifestyle factors associated with its presence. Methods Participants were recruited from the Osteoporotic Fractures in Men Study, a longitudinal study of risk factors for fractures in older men. Dental measures included clinical attachment loss (CAL), pocket depth (PD), calculus, plaque and bleeding on a random half-mouth, plus a questionnaire regarding access to care, symptoms and previous diagnosis. Results 1210 dentate men completed the dental visit. Average age was 75 years, 39% reported some graduate school education, 32% smoked 20 + pack years and 88% reported their overall health as excellent/good. In terms of periodontal health, 38% had sub-gingival calculus, 53% gingival bleeding, 82% CAL ≥5 mm and 34% PD ≥6 mm. The prevalence of severe periodontitis was 38%. Significant demographic and lifestyle factors associated with severe periodontitis in multivariate analyses included age ≥75 (OR 1.4, 95% CI 1.1-1.7) non-white race (OR 1.9, 95% CI 1.3-2.8), less than an annual dental visit (OR 1.5, 95% CI 1.1-2.0), and 20 + pack years (OR 2.1, 95% CI 1.6-2.7). Conclusion A high proportion of healthy older men have evidence of periodontal destruction which could, given the growing ageing population, have a significant impact on the dental profession's ability to provide preventive and therapeutic care. The population at highest risk of periodontitis in MrOS is older minority men who smoke and do not have annual dental visits. © 2009 The Authors.