One million individuals in the United States, predominantly males under 25 yr of age, are current or past users of anabolic-androgenic steroids. Fifty percent of these young adults administer their drugs intramuscularly, placing them at risk for infections related to injection. We present here a case report of an injection-related thigh abscess in a 26-yr-old anabolic steroid injector who did not use sterile injection technique and reported sharing multidosage vials with two other weightlifting colleagues. Reported infections associated with anabolic-androgenic steroid injection include abscesses attributable to Mycobacterium smegmatis, Staphylococcus, Streptococcus, and Pseudomonas organisms as well as HIV, hepatitis B, and hepatitis C. These infections are primarily related to nonsterile injection technique, shared injection equipment, and are avoidable with appropriate prevention techniques. Education is needed to prevent infectious complications such as abscesses and blood-borne pathogens among anabolic-androgenic steroid injectors.