Background: Pre-hospital emergency personnel plays a critical role in providing communities with essential medical care during the corona pandemic. Emergency medical services (EMS) are at the forefront of the health care system, and they are the first treatment group associated with COVID-19 patients to transfer suspected and known COVID-19 patients to medical centers. This study aims to investigate the factors affecting COVID-19 preventive behaviors in pre-hospital emergency personnel in Fars province, Iran based on protection motivation theory.Methods: This cross-sectional, web-based survey was conducted on 650 pre-hospital emergency personnel in Fars province in 2020. Data were collected by a questionnaire consisting of demographic information, protection motivation theory, and COVID-19 preventive behaviors.Results: 650 employees of Fars pre-hospital emergency and emergency bases participated in the study. The average age of participants in the study 45.14±10.37 years. There was a positive and significant correlation between preventive behaviors and constructs of the PMT model, including perceived susceptibility, severity, response efficacy, self-efficacy, response cost, and protection motivation. The response cost and protection motivation (behavioral intention) had the lowest and highest percentage of the mean from the maximum obtainable score among structures of the model, respectively. Perceived vulnerability, perceived severity, self-efficacy, and protection motivation (behavioral intention) are the strongest predictor of behavior. The variables predicted 61.3% of the variance of coronavirus preventive behaviors.Conclusion: The results of this study confirm the role of protection motivation theory in adopting preventive behavior of pre-hospital emergency personnel, it is suggested that interventional training be held with this theory, and facilitating protective behaviors as a principle in education should be considered.