ABSTRACT Background Anabolic-androgenic steroids (AAS) have positive anabolic effects on muscle mass. Some bodybuilders use high doses of AAS to build more muscle mass and strength. This study was conducted to measure the extent of AAS use among Iranian male bodybuilders and associated risk factors. Methods A cross-sectional study was carried out among 588 male bodybuilders from July to August 2020 in Isfahan. Isfahan city was divided into 15 clusters according to Isfahan municipal districts. In each cluster, three clubs were randomly selected. A self-administered questionnaire including demographic information and AAS usage data was completed by a consecutive sample of bodybuilders. Results One hundred and seventy-one (29.1%) participants were current users and 32 (7.7%) planned to use AAS in the future. AAS users had higher incomes, longer gym memberships, and more weekly sessions. They significantly used more supplements and other substances including growth hormone, caffeine, insulin, and glucocorticoid. The most prevalent AAS was testosterone enanthate. Income, length, and frequency of workouts could predict AAS use. Conclusion Increasing AAS consumption seems to become a public health concern that suggests the need to develop some new policies and programs which would educate and inform bodybuilders and coaches about the adverse effects of AAS use.