Aim of this study was to investigate the influence of the age of a study population on the association between periodontitis and ischemic stroke. Methods: 303 consecutive patients with acute ischemic stroke (T) and 300 representative population controls (C) matched for age, gender and area of resi-dence were divided into subjects with a maximum age of 60y (T: 144, C:159; group I) and those, who were older (T:159, C:141, group II). Subjects were clinically and radiographically examined for the presence of periodontitis. A questionnaire was used by trained interviewers in a face-to-face in-terview to investigate all known and/or suspected risk factors for stroke and periodontitis. Results: In group I, stroke patients showed statistically significant higher attachment loss (CAL; T: 4.0 ± 1.3 mm; C: 3.5 ± 0.8mm). There was no statistically significant difference in group II (T: 4.6 ± 1.4mm; C: 4.3 ± 1.4mm). After correction for age, gender and tooth loss, in group I a CAL of >4mm (OR 7.52; 95%-CI 2.77-20.39; p 4mm (7.40; 95%-CI 2.36-23.23; p=0.001) remained a significant risk factor. In group II in neither model any statistically significant association could be detected. Conclusion: As-sociations between periodontitis and cerebrovascular disease seem to be detectable in younger pa-tients, only. This study was funded by The German Research Council (DFG Grant# Gr1102/3-1) Schlagwörter: periodontitis, ischemic stroke, cerebrovascular disease