This chapter presents the theoretical and empirical rationale for the development of an innovative intervention for the enhancement of performance. The mindfulness-acceptance-commitment (MAC) approach to performance enhancement is based on an integration of mindfulness and acceptance-based approaches and is specifically tailored for high-performing clientele. The predominant psychological approaches have emphasized the development of self-control of internal states such as thoughts, emotions, and physical sensations and have been commonly referred to as psychological skills training (PST) procedures. The self-regulatory PST procedures most often discussed are goal-setting, imagery/mental rehearsal, arousal control, self-talk modification, and precompetitive routines. The efficacy of psychological skills training techniques and procedures for performance enhancement has been most carefully evaluated within the context of athletic performance enhancement. Mindfulness can be seen as the process that promotes greater awareness of internal experiences and the defusion of one’s thoughts, emotions, and bodily sensations.