This article evaluated the efficacy status of religious and spiritual (R/S) therapies for mental health problems, including treatments for depression, anxiety, unforgiveness, eating disorders, schizophrenia, alcoholism, anger, and marital issues. Religions represented included Christianity, Islam, Taoism, and Buddhism. Some studies incorporated a generic spirituality. Several R/S therapies were found to be helpful for clients, supporting the further use and research on these therapies. There was limited evidence that R/S therapies outperformed established secular therapies, thus the decision to use an R/S therapy may be an issue of client preference and therapist comfort. © 2009 Wiley Periodicals, Inc. J Clin Psychol 66: 1–27, 2010.