Cardiovascular diseases as well as periodontitis can be regarded as current epidemics and have become a social problem. Mean platelet volume (MPV) is a simple, routinely assessed biochemical parameter, which is becoming regarded asa new, independent risk factor of acute coronary syndromes and stroke. Assessment of a potential relationship between clinical indices of periodontal disease and MPV in relation to the presence of coronary artery disease (CAD) and chronic periodontitis. The study included 57 individuals aged from 50 to 65 years. Patients were divided into three groups. Group 1 consisted of 19 patients with previously diagnosed CAD and coexisting chronic periodontitis. Group 2 included 18 patients with diagnosed chronic periodontitis with excluded CAD. Group 3 was a control group and consisted of 20 healthy individuals without CAD or periodontitis. Unsatisfactory oral hygiene defined by plaque index (PI) was observed in all patients. Mean PI was significantly higher in Groups 1 and 2 than in Group 3 (76.7% vs. 45.7%, p < 0.01). Mean bleeding index (BI) was significantly higher in Group 2 than in Groups 1 and 3 (46.4% vs. 29.8%, p < 0.05). Mean periodontal pocket depths (PD) (2.75 mm, 2.93 mm,1.97 mm, respectively, p < 0.05, p < 0.01) and clinical attachment loss (CAL) were significantly higher in Groups 1 and 2 than in Group 3 (5.13 mm, 4.79 mm, 1.31 mm, respectively, p < 0.01). Mean WBC, fibrinogen and hsCRP were not significantly different among the examined groups (WBC 6.81 G/L vs. 6.71 G/L vs. 6.18 G/L, fibrinogen concentration 4.31 g/L vs. 3.94 g/L vs. 3.67 g/L; hsCRP concentration 4.08 mg/dL vs. 6.61 mg/dL vs. 4.33 mg/dL). In Group 1, MPV was significantly higher than in Group 3 (10.39 fL vs. 9.39 fL, p < 0.01). There was a weak, although significant, correlation between periodontal parameters and MPV and correlations between MPV and PD as well as CAL (MPV-PD: r = 0.45, p < 0.05; MPV-CAL: r = 0.42, p < 0.05). Chronic periodontitis in patients with CAD results in an increased MPV that may suggest increased platelet activity. This observation could indicate a potential pathophysiological link between chronic periodontitis and an increased risk of acute coronary syndromes.