Background: In recent decades, unsafe use of pesticides has caused different cancers in human beings as well as damages to environment and organisms. Objectives: The present study aimed to determine the predictors of safety behavior among greenhouses spray workers in Jiroft city based on Protection Motivation Theory (PMT). Methods: This cross-sectional study with descriptive-correlation approach was conducted in 2016 on 229 greenhouse spray workers in Jiroft city selected via proportional stratified random sampling using a researcher-made questionnaire. The questionnaire consisted of demographic variables and PMT constructs such as perceived vulnerability, perceived severity, costs, rewards, fear, selfefficacy, response-efficacy, and protection motivation, as well as safety behaviors. Results: All workers were male in the age range of 19 to 72 years, most of whom (47.6%) had previously been poisoned by pesticides. The mean scores of all the PMT constructs were in range of 50% to 75% except for perceived rewards that its mean score was between 75% and 100%. There was a significant correlation between response-efficacy and all the constructs at P < 0.01, except for the perceived rewards that was significant at P < 0.05. Moreover, a significant correlation was found between all the constructs other than perceived rewards and fear (P < 0.01). The predicted amount of spray workers' preventive behaviors by protection motivation theory constructs was 41% and the role of perceived vulnerability (β = 0.310), perceived severity (β = 0.303), self-efficacy (β = 0.166), and response-efficacy (β = 0.140) was greater than the role of other constructs. Conclusions: Concerning predictive power of protection motivation theory constructs for safety behaviors related to spray workers' health and due to the important role of perceived vulnerability, perceived severity, self-efficacy, and response-efficacy, educational interventions are necessary for training protective principles to prevent health problems resulted from exposure to pesticides in workers.