RESUMEN
BACKGROUND: The present research explored the effect of an educational program based on the health belief model (HBM) on prisoners' HIV preventive behaviors in the south of Iran. METHODS: The present quasi-experimental research was conducted in 2019-20 on 280 prisoners, 140 in the control group (CG) and 140 in the intervention group (IG). The sampling was simple randomized. The data were collected using a questionnaire in two parts, one exploring the demographic information and the other the HBM constructs. The final follow-up was completed 3 months after the educational intervention (8 sessions long) in November 2020. RESULTS: After the intervention, statistically significant between-group differences were found in the healthy behavior score and all HBM constructs except for the perceived barriers (p < 0.001). Perceived severity and susceptibility were found to be the strongest predictors of HIV preventive behaviors. CONCLUSION: The educational intervention showed to positively affect the adoption of preventive behaviors mediated by the HBM constructs. To remove barriers to HIV preventive behaviors or any other healthy behavior, researchers are suggested to develop multi-level interventions (beyond the personal level) to gain better findings.