Introduction: Self-medication (SM) is used in medicine without consultation with a physician which leads to serious problems, especially in women. This study aimed to investigate the effectiveness of a health promotion intervention and education based on health belief model (HBM) on improving the preventive behaviors of self-Medication among women in Tehran, Iran. Methods: A quasi-experimental survey was carried out among 88 women in 4 selected health institutions of one of the districts in Tehran, Iran. A multi-stage random sampling method was carried out to select the participants. The intervention group received the educational module based on constructs of HBM on the prevention of SM, free medical facilities, and video about SM. The outcomes were assessed at baseline and one month after intervention by validated questionnaire on constructs of HBM and checklist of behavior in self-medication in both groups. The data were analyzed by SPSS16 using descriptive and analytical statistical tests. Result: At baseline, there was no significant difference between the mean scores of knowledge, perceptions (self-efficacy, susceptibility, severity, perceived benefits and barriers, self-Efficacy) , and prevention of self-medication behavior in both intervention and control groups (p > 0.05); but after the intervention, there was a significant difference between the mean scores of both groups in all variables (p<0.001). Also, post-test results showed the considerable promotion of perceived barriers scores in the intervention group, especially on simple and fast inaccessibility to physician and high physician expenses. Conclusion: Educational and promotional intervention based on the health belief model is effective in improving the perceptions and behavior of women in the prevention of self-medication.