As a population-based, longitudinal study of nearly 6000 older American adults, the Cardiovascular Health Study provides an excellent opportunity to assess the roles of traditional and novel cardiovascular risk factors in the development of coronary heart disease. Cardiovascular Health Study investigators have analyzed both traditional risk factors, such as diabetes, hypertension, and smoking, and new risk factors, such as hemostatic factors, inflammatory markers, exposure to infectious agents, and genetic determinants. These analyses have led to several important conclusions. First, older adults without previous cardiovascular events have a tremendous burden of subclinical vascular disease, which may change how physicians view risk factor modification in this age group. Second, some traditional cardiovascular risk factors lose importance as predictors of cardiovascular disease among older adults. Third, even modest elevations in fasting blood glucose or systolic blood pressure-below the levels used to define diabetes or hypertension-may have prognostic implications. Fourth, novel cardiovascular risk factors may add further information about cardiovascular disease risk in older adults. Promising potential candidates identified in the Cardiovascular Health Study include markers of hemostatic activation, fibrinogen, factor VIII coagulant activity, C-reactive protein, and exposure to herpes simplex virus-1 and possibly chlamydia. Future Cardiovascular Health Study investigations will help to clarify which combination of traditional and newer risk factors provides the best estimate of cardiovascular risk for older adults.