BACKGROUND: In recent years positive effects of Yoga (as a kind of spiritual exercise) in regards to subjective well-being and physical health can be found as well documented in the literature. METHOD: Based on a construct-psychological approach a newly developed scale for the assessment of Yoga involvement (immersion) was validated on a sample of 233 non-clinical subjects (210 females) by means of socio-demographic and well established psychometric parameters of psychological well-being and psychiatric symptoms. Furthermore, the group of yoga practitioners was compared with a control group consisting of 93 gymnastics practitioners (83 women) with respect to these parameters. RESULTS: The amount of Yoga Immersion (YI) can be reliably assessed by means of the one-dimensional YI-scale (10 items) and shows to be strongly correlated with Mindfulness (r = .56; p < .01), Inner Correspondence (r = .61; p < .01) and Religious/Spiritual Well-being (r = .68; p < .01). Furthermore highly yoga-immersive practitioners exhibited a significant higher amount of psychological well-being (p < .01) compared to marginally/moderately yoga-immersive and gymnastics practitioners. The Yoga-group also showed a lower amount of psychiatric symptoms (e.g. depression; p < .01). CONCLUSIONS: The globally postulated positive relationship between Yoga-practicing and mental health could be confirmed; thereby the impact of YI can be assumed as central. Further randomized controlled trial research focusing on the health/disease-related aspects of YI might be conducted especially in clinical groups.