Over the past 30 years the practice of meditation has become increasingly popular in clinical settings. In addition to evidence-based medical uses, meditation may have psychiatric benefits. In this review, the literature on the role of meditation in addressing psychiatric issues, and specifically substance use disorders, is discussed. Each of the three meditation modalities that have been most widely studied-transcendental meditation, Buddhist meditation, and mindfulness-based meditation-is critically examined in terms of its background, techniques, mechanisms of action, and evidence-based clinical applications, with special attention given to its emerging role in the treatment of substance use disorders. The unique methodological difficulties that beset the study of meditation are also considered. A brief discussion then integrates the research that has been completed thus far, elucidates the specific ways that meditation may be helpful for substance use disorders, and suggests new avenues for research.