An association between total white blood cell (WBC) count and the risk of coronary heart disease (CHD) is well known. In the present study, we investigated the relationship between WBC counts and other clinical factors including coronary risk factors, and periodontal disease in 1,620 adults. Factors found to have a significant association with the WBC count by multivariate regression analysis were age (negative association), body mass index (negative association), serum triglycerides, high-density lipoprotein cholesterol (negative association), and periodontal levels in the smoking group.Whereas, in the non-smoking group, systolic blood pressure and diastolic blood pressure (negative association) were included and serum triglycerides were excluded.Non-smoking subjects who were free of periodontal disease had a mean WBC count of 4.69 +/- 1.0 x 109 cells/l. This value can be used as a reference for WBC counts in healthy subjects. Our data suggest that values significantly higher than this could be an important indicator of inflammation derived from cigarette smoking or periodontal disease. Further study is necessary to determine whether an improvement in the WBC count could prevent the occurrence of CHD.