Background & Objectives : Shift work has been recognized as an important tool for organizing of work in developing countries. The disturbed sleep, fatigue and accident is the most common health ‐ related effects of shift work. The aim of this study was to evaluate the severity of fatigue and sleepiness between shift and non-shift workers and its relation to occupational accidents.

  Methods : This cross-sectional study was carried out in Sugar Factory located in Isfahan city. Using simple randomized sampling technique, 120 workers with an average age of 32 years for night work and 33 years for day work were selected. ISI and Epworhth questionnaires and Fatigue Scale were used to determine the prevalence of symptoms of Sleepiness and fatigue. The data was analyzed using SPSS20 software and applying descriptive statistics, Pearson correlation test and t-test.

  Results : Results showed that the fatigue score among shift workers was 4.41. In all symptoms associated with fatigue average scores of night shift were higher than day shift and there was a significant difference between them. There was a significant relation between the symptoms of fatigue with insomnia severity index and accidents.

  Conclusion : The rate of fatigue and the number of the work accidents was more in the shift workers compared with non shift workers. The rate of accidents was more common in people who had more severe drowsiness.