Although existing measures of religiousness are sophisticated, no single approach has yet emerged as a standard. We review the measures of religiousness most commonly used in the religion and health literature with particular attention to their limitations, suggesting that vigilance is required to avoid over-generalization. After placing the development of these scales in historical context, we discuss measures of religious attendance, private religious practice, and intrinsic/extrinsic religious motivation. We also discuss measures of religious coping, wellbeing, belief, affiliation, maturity, history, and experience. We also address the current trend in favor of multi-dimensional and functional measures of religiousness. We conclude with a critique of the standard, "context-free" approach aimed at measuring "religiousness-in-general", suggesting that future work might more fruitfully focus on developing ways to measure religiousness in specific, theologically relevant contexts.