['Periodontitis is a chronic infectious disease and has been associated with cardiovascular diseases (CVD). We investigated whether plasma levels of markers of a prothrombotic state were elevated in patients with periodontitis in comparison with healthy controls.', 'Untreated patients with moderate (n=53) and severe periodontitis (n=38) and healthy controls (n=39) were recruited. Levels of von Willebrand factor (vWF), prothrombin fragment 1+2 (F1+2), plasminogen activator inhibitor-1 (PAI-1) activity and D-dimer were measured as markers of a prothrombotic state.', 'The erythrocyte sedimentation rate (ESR), plasma C-reactive protein (CRP) and leucocyte counts (WBC) were significantly higher in patients with periodontitis. No statistically significant difference was found among the three groups for vWF (p=0.264), F1+2 (p=0.295) and D-dimer (p=0.572). However, PAI-1 was clearly elevated in the severe periodontitis group (p=0.001), even after adjusting for potential confounding factors (p(adj)=0.004). Moreover, more patients than controls were having vWF and PAI-1 levels above the respective population medians.'] Is periodontitis characterized by elevated PAI-1 activity?