In this chapter, we argue that state and trait mindfulness and mindfulness-based practices in the workplace should enhance employee outcomes. First, we review the existing literature on mindfulness, provide a brief history and definition of the construct, and discuss its beneficial effects on physical and psychological health. Second, we delineate a model of the mental and neurobiological processes by which mindfulness and mindfulness-based practices improve self-regulation of thoughts, emotions, and behaviors, linking them to both performance and employee well-being in the workplace. We especially focus on the power of mindfulness, via improved self-regulation, to enhance social relationships in the workplace, make employees more resilient in the face of challenges, and increase task performance. Third, we outline controversies, questions, and challenges that surround the study of mindfulness, paying special attention to the implications of unresolved issues for understanding the effects of mindfulness at work. We conclude with a discussion of the implications of our propositions for organizations and employees and offer some recommendations for future research on mindfulness in the workplace.