Experiential mindfulness meditations are essential components of mindfulness-based interventions (MBIs), are included in several other forms of psychotherapy, and are used by many people as a stand-alone practice. In this chapter, we explore the role of experiential mindfulness meditation within psychotherapy and how meditation can impact state and trait self-regulatory change. We will review previous research that has utilised the experimental method to isolate and test the mechanisms of mindfulness meditation practice as an agent of change. We conclude the chapter with recommendations to researchers who are designing experimental studies in this field. The chapter reports on the evidence supporting the active contribution of experiential mindfulness meditation when embedded in multicomponent interventions and as a stand-alone practice, particularly in positively impacting emotion regulation and attention. The authors call for more transparency and replication of experimental methods and results and a greater awareness of how methodological choices are impacting the detection of effects.