Epidemiologic studies of the effects of religion on blood pressure suggest that religious commitment is inversely associated with blood pressure and that several religious denominations or groups have relatively low rates of hypertension-related morbidity and mortality. In this review, we examine the implication that certain characteristics and functions of religion account for this association, and we posit 12 possible explanations for this finding. We propose that a salutary effect of religion on blood pressure can be explained by some combination of the following correlates or sequelae of religion: the promotion of health-related behavior; hereditary predispositions in particular groups; the healthful psychosocial effects of religious practice; and, the beneficial psychodynamics of belief systems, religious rites, and faith. Since past epidemiologic studies may have been methodologically limited or flawed, possible explanations for the findings of these studies also include epistemological confusion, measurement problems, and analytical errors. Finally, for the sake of completeness, two more speculative hypotheses are identified: superempirical and supernatural influences or pathways.