Objective: Translate the original English version of the Rapid Office Strain Assessment [ROSA] into Thai version and evaluate the validity and reliability of Thai ROSA in office worker.

Materials and Methods: The original version of ROSA was translated into Thai using a standard forward-backward procedure and Translation Equivalence testing. The content validity was approved by four experts in ergonomic and occupational health. Inter-rater reliability was examined by researcher and other expert in ergonomics in 48 subjects, university office workers. All subjects were re-assessed one week later by the researcher to obtain intra-rater reliability.

Results: The Thai version of ROSA, translated according to international standard, had universal agreement calculation method (S-CVI/UA) = 0.80, scale-level content validity index (S-CVI/Ave) = 0.95 and very high inter- and intra-rater reliability as following ICC final score = 0.99 and ICC final score = 0.91.

Conclusion: The Thai version of ROSA is a valid and reliable measurement method for Ergonomic Assessment in Thai office worker.

Keywords: The rapid office strain assessment [ROSA], Reliability, Validity, Office worker, Thai