Background and aims: Fatigue is the risk factor of musculoskeletal disorders and the aim of ergonomics is prevention from it. Decline in employee’s performance, safety and health are consequences of fatigue. The assessment of fatigue is necessary for its control. This study is going to provide valid and reliable Persian version of Swedish Occupational Fatigue Inventory for measuring occupational fatigue.

  Methods: This analytical study population was 77 filling-station operators in Hamadan. Concordance among ergonomic experts and validity of the Persian version of Swedish Occupational Fatigue Inventory were assessed with Cohen's Kappa coefficient and content validity, respectively. To determine structures and principles of inventory, exploratory factor analysis was used. Cronbach’s alpha coefficient was used to determine the reliability of SOFI-translated Inventory. SPSS.16 software was used for data analysis.

  Results: In Persian version of SOFI ) P-SOFI ( , Cohen Kappa agreement coefficient among experts was 0.812, with 95% CI: 0.622, 0.974. In exploratory factor analysis after oblimin turning, three factors were extracted from the Inventory. Reliability coefficient of each 3 factors [functional, physical, conceptual] in Persian version was at least 0.899 and a reliability of 0.921 was determined for total inventory. Internal consistency coefficient of the inventory was 0.894.

  Conclusion: The result indicated that P-SOFI has a fair validity and reliability. Whereas 3 obtained factors [functional, clinical and psychological] define the 72% of the total inventory variance, the appropriateness of the factors is reliable. This inventory can be applied for the prevention of fatigue and programming of health-related interventions in workplace.

  Keywords: Occupational fatigueInventory, Ergonomics, Validity and Reliability