This article reviews the theory, clinical application, and empirical findings on mindfulness-based cognitive therapy (MBCT) for mental health and addictive disorders. Expanding upon the research demonstrating the efficacy of cognitive-behavioral therapy (CBT) for addiction, this article develops and explores the rationale for combining mindfulness-based interventions with evidence-based CBTs in treating addictive disorders, with an emphasis on substance use disorders with co-occurring mood disorders. This article proposes that deficits in affect--regulation related to the behavioral and emotional effects of neurobiological changes that occur with long-term substance abuse--pose a unique set of challenges in early recovery. Prolonged use of addictive substances impairs the brain pathways that mediate certain affect regulation functions. These functions involve attention and inhibitory control, the saliency of and response to addictive versus natural reward stimuli, and the ability to detach or maintain perspective in response to strong emotional states. In treating this affective dysregulation, which can contribute to the vulnerability to relapse in the early stages of recovery, the affect-regulation-specific focus of MBCT adds a valuable element to augment CBT for addiction. Summarizing magnetic resonance imaging and positron emission tomography findings on the effects of MBCT and the neurobiology of drug addiction, this article outlines directions for further research on potential benefits of MBCT for the recovering individual. Finally, this article describes a structured protocol, developed at the Mount Sinai School of Medicine in New York City, which combines CBT with mindfulness-based intervention, for the treatment of affect-regulation issues specific to co-occurring addictive and mood disorders.