Interest in the clinical use of mindfulness practices has expanded rapidly in recent years. To provide a direction for future research in this area, this article identifies the primary scientific and clinical questions regarding the clinical application of mindfulness practice. In particular, the following questions are addressed: What is mindful‐ness? What are the consequences of separating mindful‐ness from its spiritual and cultural origins? Is mindfulness training an efficacious treatment intervention? What are the active or essential ingredients of mindfulness training? Can mindfulness enhance clinical practice apart from its role as a clinical intervention? How does mindfulness work? How should therapists be trained in order to deliver mindfulness interventions competently? Is mindfulness training amenable to widespread dissemination?