en <div style=text-align: justify;><strong>Aims:</strong> The prevalence of Diabetes type 2 has been increased significantly during recent years. So, prevention is necessary from adolescence. This study aimed to investigate the effect of Health Belief Model-based education on preventive behaviors of Diabetes type 2 in male adolescences.<br> <strong>Materials & Methods:</strong> This semi-experimental study was conducted on 208 secondary school students of Hamadan city (104 students in an experimental group and 104 students in a control group) in 2018, who were selected using the stratified-proportional sampling method. Data were collected using a researcher-developed questionnaire including demographic, awareness, model constructions, and preventive behavior. Afterward, an educational intervention was implemented in the experimental group based on Health Belief Model in four 45-60 minute sessions. After one month, the data were recollected from the two groups and analyzed using Chi-square, t-test, and linear regression by SPSS 16 software.<br> <strong>Findings:</strong> Comparing the scores of awareness, Health Belief Model constructs, and student’s preventive practices revealed no statistically significant differences between the two groups at the beginning of the study (p>0.05). However, after the intervention, significant differences were observed between the two groups regarding awareness, the Health Belief Model constructs, and student’s preventive practices (p<0.05). Linear regression analysis indicated that self-efficacy was the most important independent predictor of type-2 diabetes-preventative behavior (p<0.05). <span dir=RTL></span><br> <strong>Conclusion:</strong> Health Belief Model-based education is effective in promoting type-2 diabetes prevention behaviors in students.</div> Health Belief Model, Diabetes Mellitus, Type 2, Prevention and control, Adolescent 209 216 http://hehp.modares.ac.ir/browse.php?a_code=A-10-58595-1&slc_lang=en&sid=4 M. Khodaveisi 1003194753284600198034 1003194753284600198034 No Department of Community Health Nursing, Chronic Diseases (Home Care) Research Center, Hamadan University of Medical Sciences, Hamadan, Iran Sh. Peyghani Asl 1003194753284600198035 1003194753284600198035 No Department of Community Health Nursing, Hamadan University of Medical Sciences, Hamadan, Iran M. Purabdollah 1003194753284600198036 1003194753284600198036 No Department of Community Health Nursing, Faculty of Nursing and Midwifery, Tabriz University of Medical Sciences, Tabriz, Iran L. Tapak 1003194753284600198037 1003194753284600198037 No Department of Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran F. Cheragi 1003194753284600198038 1003194753284600198038 No Department of Pediatric Nursing, School of Nursing and Midwifery, Chronic Diseases (Homecare) Research Center, Hamadan University of Medical Sciences R. Amini aminiroy@gmail.com 1003194753284600198039 1003194753284600198039 Yes Department of Community Health Nursing, Chronic Diseases (Home Care) Research Center, Hamadan University of Medical Sciences, Hamadan, Iran