Purpose: The purpose of this study was to identify factors affecting health promotion behavior among workers with high risk of metabolic syndrome. This study was based on the planned behavior theory. Methods: The participants were 167 workers at high risk of metabolic syndrome. Data were collected using a structured questionnaire. Surveyed variables were attitude, subjective norm, perceived behavioral control, intention, and health promotion behavior. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson’s correlation coefficients, and hierarchical regression analysis with SPSS/WIN 22.0. Results: Perceived behavioral control affected the intention of health promotion behavior among the workers with high risk of metabolic syndrome. It explained 62% of variance in the intention of health promotion behavior (F=40.09, p<.001). Perceived behavioral control and occupation affected health promotion behavior among the risk workers with high risk of metabolic syndrome. The two factors explained 16% of variance in health promotion behavior (F=4.95, p<.001). Conclusion: The findings of this studysuggest that perceived behavioral control is the only factor affecting health promotion behavior when the theory of planned behavior was applied. Therefore, intervention programs for improving health promotion behavior should be focused on strengthening perceived behavioral contro.