Fatigue is one of the problems often experienced by workers which can lead to fatal events. Workers with longer working hours tend to be experience fatigue. An operator has a duty to operate a machine and standby for 8 hours in order to always supervise the production of which if it is not given any enough rest time, it will be at risk of fatigue. The aims of the study is to find out the difference in work fatigue between workers in Division A who work on 5-days– 2-day off (40 hours per week) shift pattern with division B who work on 6-days – 1-day off (48 hours per week) shift pattern. This research was analytic observational methods of data collection and cross sectional design. The sample in this study was operators in division A and B taken from the population usingstratified random sampling technique. Variable testing performed using statistical test of mann-whitney test for ordinal data. Different test show that there is a difference in work fatigue between the workers in division A and B who have different shift patterns. Both of division are exposed to noise and work climate that are not up to standard, but division B was exposed longer each week, indicating that division B workers are more likely to experience work fatigue with more severe categories.