Our aim in this cross-sectional study was to investigate the predictors of the stages of change in mammography adoption (MA) based on Health Belief Model among Iranian women. Through multistage cluster sampling, we recruited and interviewed 1131 women older than 40. After statistical adjustment for other risk factors, perceived barriers (OR D 0.84, 95% CI D .81-.87) and benefits (OR D 1.17, 95% CI D 1.11-1.24) were significant predictors for MA. Majority of the women were in the pre-contemplation and contemplation stages of change for MA. Our findings are informative for the development of targeted interventions to foster MA among women.