Aims: The aim of this study was to assess the effect of shift work on metabolic syndrome in Iran Polyacryl Corporation workers. Materials and Methods: This retrospective cohort study was conducted on Iran Polyacryl Corporation workers for 10 years. The incidence of metabolic syndrome was assessed between shift workers and day workers. For analysis of the effects of shift work on six different combinations of metabolic syndrome, Logistic regression was used, and information was analyzed with using Statistical Package for Social Science-SPSS version 18. Results: The mean triglyceride, body mass index, total cholesterol, and systolic blood pressure was higher in the day workers than rotating shift workers, but the difference was not significant (P value > 0.05). Logistic regression showed a significant inverse relationship between shift work and combination of three metabolic syndromes with a relative risk (RR) and %95 confidence interval (CI) of 0.24 and (0.06-0.94), respectively. Although shifts work increased risk of combination of numbers 2 (IFG, BP, and BMI) and 4 (IFG,TG, and BMI) metabolic syndrome 66% and 6%. These differences were not significant (RR = 1.66, %95 CI ; 0.81-3.37 and RR = 1.06, %95 CI ; 0.72-1.58 respectively). Other combinations of metabolic syndrome had a non-significant inverse relationship with shift work (P value > 0.05). Conclusion: Our findings indicate that rotating shift work not increases the risk of metabolic syndrome and different combinations. However, significantly decreased risk for developing combination 3 (Impaired fasting glucose, hypertension, and positive micro albuminuria).