Objectives: The aim of this study was to examine how different levels of yoga involvement are related to different parameters of mental health and illness. Design and Setting: A total sample of 455 participants (410 females) was investigated by means of an internet survey. 362 yoga practitioners (327 females) rated their degree of yoga involvement on the Yoga Immersion Scale. A control group was comprised of 93 gymnastics practitioners (83 females). Main outcome measures: All participants completed the Multidimensional Inventory for Religious/Spiritual Well-Being, the Freiburger Mindfulness Inventory and the Brief Symptom Inventory for psychiatric symptoms. Results: Highly involved yoga practitioners exhibited a significantly increased amount of mindfulness and religious/spiritual well-being (both p<.01) and lower psychiatric symptoms such as depression (p<.01) compared to those who were only marginally/moderately yoga-involved or who were in the gymnastics control group. Conclusions: In accordance with the literature, yoga practice might have its biggest impact on mental health when it is part of a practitioner’s worldview. Further research focusing on the impact of yoga involvement in clinical groups is encouraged.