This chapter provides a straightforward guide to the emerging work on mindfulness in cognitive-behavioral science, based both on the experience with mindfulness practices and on the rapidly-evolving empirical literature on mindfulness. Acceptance and commitment therapy (ACT) is a behavioral intervention rooted in basic research on language and cognition. The goal of traditional cognitive-behavioral therapy (CBT) is to reduce symptoms, whereas, the goal of ACT is valued living irrespective of symptoms. Mindfulness-based cognitive therapy is an eight-week group experiential education program designed to prevent relapse in patients with recurrent depression. The chapter discusses empirical studies of ACT, mindfulness-based cognitive therapy (MBCT), and dialectical behavior therapy (DBT). Several outcome studies have found that DBT is a promising approach, and no other therapy has demonstrated superiority to DBT. A review of the efficacy of mindfulness-based treatments has been recently provided by Stefan Hofmann and colleagues.