A higher white blood cell (WBC) count has been shown to be a risk factor for myocardial infarction and stroke in middle-aged populations. This study evaluated the relation between baseline WBC count and other risk factors, as well as subclinical and prevalent disease, in the Cardiovascular Health Study, an epidemiologic study of coronary heart disease and stroke in 5, 201 persons aged 65 years or older. Baseline data were collected over a 12-month period in 1989–1990. WBC counts were statistically significantly higher in people with prevalent and subclinical atherosclerotic cardiovascular disease than in those who were free of disease. WBC counts correlated (p < 0.01) positively with coagulation factors, measures of glucose metabolism, creatinine, smoking, and triglycerides. In contrast, WBC counts correlated negatively with high density lipoprotein cholesterol, forced expiratory volume, forced vital capacity, and height. The correlations between WBC counts and nsk factors were similar in both the entire cohort and the subgroup of persons who had never smoked. The authors conclude that WBC counts in the elderly are associated with prevalent and subclinical atherosclerotic cardiovascular disease, as well as its risk factors. Am J Epidemiol 1996; 143: 1107–15.