This article reviews the empirical research on prayer and health and offers a research agenda to guide future studies. Though many people practice prayer and believe it affects their health, scientific evidence is limited. In keeping with a general increase in interest in spirituality and complementary and alternative treatments, prayer has garnered attention among a growing number of behavioral scientists. The effects of distant intercessory prayer are examined by meta-analysis and it is concluded that no discernable effects can be found. The literature regarding frequency of prayer, content of prayer, and prayer as a coping strategy is subsequently reviewed. Suggestions for future research include the conduct of experimental studies based on conceptual models that include precise operationally defined constructs, longitudinal investigations with proper measure of control variables, and increased use of ecological momentary assessment techniques.