Previous research has documented lower cancer mortality rates among religious groups characterized by doctrinal orthodoxy and behavioral conformity. In addition, there is evidence that the general population in an area with a high concentration of religious participants may experience health benefits resulting from diminished exposure to or increased social disapproval of behaviors related to cancer mortality. This research examines the effect of religious concentration and denominational affiliation on county cancer mortality rates. Our findings suggest that religion has a significant impact on mortality rates for all malignancies combined, for digestive cancer, and for respiratory cancer when we control for demographic, environmental, and regional factors known to affect cancer mortality. These results provide new insight into the relationship between religion and health at the macro or community level and suggest that the influence of religion on social structure warrants further attention.