Spirituality is an important aspect of health care that is not often addressed in modern day primary medical practice. Controversy surrounds the role of spiritual issues in medical practice. Some of this stems from confusing spirituality with religion. This paper distinguishes between spiritual and religious issues and reviews the history of these issues in medicine, the growing medical literature in this area, and some practical guidelines for the practicing physician. The authors conclude that, when appropriate, spiritual issues should be addressed in patient care since they may have a positive impact on patient health and behavior, and recommend that the medical model be expanded to a biopsychosocial-spiritual one. The guidelines developed by the American Psychiatric Association provide a useful model for the practicing physician to follow. More research is needed in this area, but the authors conclude that enough is already known to support the inclusion of spiritual issues in medical education.