Baer (2003; this issue) has provided a thoughtful conceptual and empirical review of mindfulness‐based clinical interventions, emphasizing the need for further research. In this commentary we elaborate on some of the areas needing further study. The promising initial data suggest a need for basic experimental and treatment outcome research in order to determine active ingredients and mechanisms of action in mindfulness‐based interventions. In addition, questions remain regarding the optimal mode of delivery of this treatment, as well as how to integrate the non‐striving aspect of mindfulness into clinical intervention.