The nonmedical use of anabolic-androgenic steroids (AAS) appeals to athletes across several sports, particularly those whose activity makes muscle size and strength advantageous, and in individuals (usually men) with body dysmorphic disorder. Patterns of nonmedical use, including supratherapeutic doses of illicitly obtained drugs, increase the risk for adverse psychiatric and other medical consequences. Although AAS users may be more likely to consult physicians for nonpsychiatric medical consequences than changes in their mental status, it is argued that the motivation for persistent use despite adverse consequences is sustained in large part by psychological variables. Therefore, all physicians who treat nonmedical AAS users will benefit from an understanding of these psychological variables, including the potential for AAS to cause dependence. This article aims to aid such understanding, and guidelines are suggested for assessment and treatment of nonmedical AAS users.