Anabolic androgenic steroids (commonly known as anabolic steroids) are synthetic derivatives of the hormone testosterone. They are being increasingly used by professional and recreational athletes to enhance performance, and by men and women to improve physical appearance. This article discusses the characteristics of such steroid ‘misusers’ and the techniques of use. It highlights the psychiatric complications associated with these steroids, including increased risk of aggression, personality disorders, psychosis and mood disorders, particularly manic symptoms. Medical complications of steroid use are common and frequently reversible. Use is associated with an increased risk of injury, cardiovascular events, gastrointestinal complications, virilisation in women, and gynaecomastia and testicular atrophy in men. Whether addiction to these steroids can occur is debatable, but there is evidence for dependence and a withdrawal syndrome. Steroid use may be a ‘gateway’ to other addictions. Users are often reluctant to seek treatment and the psychiatrist's role in the recognition and management of use is presented.