The Millon Adolescent Personality Inventory and the Profile of Mood States were used to assess a broad range of psychological characteristics in 24 adolescent athletes who reported steroid use. In addition, a steroid knowledge questionnaire was administered and an evaluation of physical symptoms of steroid use was conducted. Corresponding data were obtained from 24 adolescent athletes who did not use steroids, and 24 nonathletic adolescents. Although some personality variables differentiated between athletes and nonathletes, no personality variables significantly differentiated between athletes who used steroids and athletes who did not use steroids. Steroid users, however, had significantly higher levels of muscular density and hardness, bloating, gynecomastia, and acne than did athletes who did not use steroids; steroid users who were currently on a steroid use cycle had significantly more depression, anger, vigor, and total mood disturbance than those who were not on a cycle. Prospective longitudinal studies are needed to develop our understanding of psychological issues related to adolescent steroid use.