This correlational study explored the psychological antecedents of 253 Iranian gym users' intentions to use the anabolic-androgenic steroids (AAS), based on the Theory of Planned Behavior (TPB). The three predictor variables of (1) attitude, (2) subjective norms, and (3) perceived behavioral control accounted for 63% of the variation in the outcome measure of the intention to use the AAS. There is some support to use the TPB to design and implement interventions to modify and/or improve individuals' beliefs that athletic goals are achievable without the use of the AAS.