Background: Promoting awareness and correcting health beliefs about preventive behaviors in adolescents and young people are the most effective ways to prevent the transmission of HIV/AIDS. This study was conducted to assess the influence of the educational intervention on the promotion of perceived self-efficacy to inhibit HIV/AIDS among high school students. Methods: This quasi-experimental investigation included 230 high school students in Asadabad and was conducted in 2021. Following the selection of students by the multi-stage cluster sampling method, they were allotted into two equal (intervention and control) groups of 115 individuals. The educational program for the intervention group included five one-hour sessions of the students’ social network (Shad), which was implemented by a participatory method based on questions and answers and group discussion, as well as practical performance. A reliable and valid questionnaire comprising three parts (personal attributes, awareness, and health belief model [HBM] constructs) was employed for data collection. The collected data were analyzed using different tests, including Fisher’s exact test, the chi-square test, ANCOVA, and independent and paired sample t tests in SPSS software, version 16. Results: Educational intervention based on HBM not only affected the promotion of awareness (P<0.05), self-efficacy, perceived susceptibility, severity, and benefits but also reduced students’ perceived barriers to preventive behaviors (P<0.05). Conclusion: Our findings revealed that the educational intervention based on HBM affected health belief constructs concerning HIV/AIDS. Thus, the results of this study can be beneficial for school health education and health educators who design disease education programs.