Background & Aim: Prostate cancer is the most common malignant cancer in men and is the second leading cause of death in men after lung cancer. In describing the epidemiology of prostate cancer, it is considered a preventable disease. The aim of this research was to investigate and explain the preventive behaviors of prostate cancer based on the structures of the health belief model among male employees of Fasa University of Medical Sciences . Materials and Methods: The present research is a descriptive-analytical study; we performed it on 263 male employees of medical sciences university selected by multi-stage cluster sampling in Fasa university of Medical Sciences. Data collection tool was a questionnaire including demographic characteristics, questions related to the structures of the health belief model and questions of health performance expression. We analyzed data using descriptive and inferential statistical methods (frequencies, mean, standard deviation, Pearson correlation coefficients and linear regression) in SPSS software version 22 . Results: In this research, we observed a significant relationship between the mean scores of perceived sensitivity, perceived benefits and barriers, and self-efficacy on the one hand and the performance of medical staff regarding prostate cancer prevention behaviors on the other (P <0.001). We found no significant relationship between perceived intensity and preventive performance of male medical staff (P <0.05). Among the components of the health belief model, perceived barriers and benefits and self-efficacy were the most important predictors of preventive performance of medical staff regarding prostate cancer . Conclusion: The present study suggests that health care providers should pay attention to predictive components such as perceived barriers, perceived benefits, and perceived selfefficacy when designing and implementing health education programs about prostate cancer