Research in the field of mind-body medicine focuses on the complex interaction of psychoemotional, social, spiritual, experiential, and behavioral elements and their impact on health and the handling of disease. Specific approaches intend to investigate and promote patients' own abilities and resources to manage their respective stressors, that is, coping strategies, relaxation techniques, mindfulness meditation, yoga, rituals, prayer, spirituality, and religiosity. An increasing number of published studies have examined the connection between spirituality/religiosity, health, and quality of life. However, the impact of a person's religiosity/spirituality on health is multifaceted and is fraught with methodological controversy since one has to deal with cognitive approaches (specific attitudes and beliefs), emotions, practices (spiritual/religious and secular forms), specific behaviors, reactive strategies to deal with illness (coping), and spirituality/religiosity-based interventions (i.e., meditation, mindfulness, and prayer). Because of this complexity, an interdisciplinary perspective is required for research as well as clinical care. We would broadly define spirituality as all attempts to find meaning, purpose, and hope in relation to the sacred or significant (which may have a secular, religious, philosophical, humanist, or personal dimension). In particular, spirituality and spiritual practices have commitment to values, beliefs, practices, or philosophies which may have an impact on patients' cognition, emotion, and behavior. Thus, personal spirituality in this sense may influence patients' sense of coherence and their ability to cope with stress, loss, and illness. Spirituality can also have an influence on patients' health behaviors and healthcare decision making, and it can be critically enabling people to reframe their situation. Spirituality can also affect how people relate to meaningful others (i.e., friends, family, and health professionals) who may be significant in their lives. Spirituality can also include people's understanding of the role and importance of transcendence in their lives; however, they may define the term. This special issue enlisted experts from different disciplines to contribute to new research on the growing body of evidence that spirituality/religiosity impacts health and illness. However, we are aware of the fact that many questions still remain unaddressed and encourage future research. Arndt Bussing Klaus Baumann Niels Christian Hvidt Harold G. Koenig Christina M. Puchalski John Swinton