This chapter provides a conceptual model of the potential influences through which religiousness and spirituality (R/S) may influence physical health and reviews the literature from the perspective of this model. When possible, this chapter provides R/S and health-specific attention to R/S and health in minority populations in the US and in diverse populations throughout the world. It is important to keep in mind that this research is almost exclusively correlational. Therefore, we must always keep in mind the possibility of unmeasured third variables even in the most rigorously designed epidemiological studies.