The purposes of this study were to estimate the prevalence of metabolic syndrome and to investigate the risk factors associated with metabolic syndrome in Korean workers. This is a secondary data analysis study using the data set from the Korean National Health and Nutrition Examination Survey IV. A total of 1,545 workers over 20 yr of age were included in this analysis. The prevalence of metabolic syndrome was determined using the modified National Cholesterol Education Program Adult Treatment Panel III criteria. Waist circumference was based on the study of obesity guidelines. The overall prevalence of metabolic syndrome among Korean workers was 21.0% (28.5% men, 11.8% women). In a multiple logistic regression analysis, male workers with high job control and heavy alcohol consumption were significantly associated with metabolic syndrome. For women, low job control and current smoking increased the risk of metabolic syndrome. The risk of developing metabolic syndrome is strongly associated with level of job control in both male and female workers. These findings suggest that behavioral lifestyle modifications, including smoking cessation, moderating alcohol consumption, and controlling work-related factors and job control in the workplace should be considered for the prevention and management of metabolic syndrome in Korean workers.