Background and Aims Tools for evaluation of code discomfort are tools that can be used for the prevention of musculoskeletal discomfort in industrial settings. Musculoskeletal disorders are serious health cancern in the developed world. The Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) that are designed to evaluate the musculoskeletal disorders by the time being, are translate in diverse languages and being implemented in many coun tries. However, CMDQ is not translated into Persian language in Iran. The aim of this study was to translate, accridate and validated the CMDQ in Persian version in order to implementation of this tool in Iran and to establish the standard tool for ergonomic research. Methods This analytical study was performed to determine the validity and reliability of translated Persian version of the CMDQ for implementation in steel industrial settings. In order to implement this tool for Iranian workers, the Farsi version of the CMDQ was prepared using the Forward-Backward translation method. Then the translated version of the questionnaire was distribute between 100 of workers in Kashan city of steel industries in a randomized manner. In order to determine the validity for the severity of discomfort, the Visual Analog Scale (VAS) was completed by all workers. The reliability of the questionnaire was determined using Cronbach's alpha Coefficient. Results In order to analysis the validity of the questionnaire for the severity of the pain and discomfort the Kappa coefficient was implemented and for the frequency of pain and discomfort the Spearman correlation coefficient was used. However, in order to analysis the reliability of the questionnaire, Cronbach's alpha Coefficient 0.986 were determined. The Cronbach's alpha Coefficient for all three sections of frequency of discomfort, severity of discomfort and interference scales were determined 0.955, 0.961, 0.969 respectively. Conclusion The Farsi version of the CMDQ is the appropriate tool for investigation of the level of musculoskeletal disorders in Iranian workers that can be used as a part of ergonomic research and Health surveillance programs in order to prevent the musculoskeletal disorders.