Objectives: To explore the content validity and the internal consistency of the diabetes Self-management Questionnaire (DSMQ) for persons with T2DM in Thailand.Methods: Diabetes Self-management Questionnaire (DSMQ) was developed in English.The translation of DSMQ into Thai language was performed by native Thai translators.A panel of five experts in Thailand evaluated the translation.Content validity was quantified by the content validity index (CVI).A crosssectional design was used to test internal consistency by calculating Cronbach's alpha.Results: The DSMQ contains 16 items.There are eleven items (69%) which showed excellent CVI;two items (12.5%) showed good CVI and three items showed acceptable CVI.The average scale of CVI was 0.90.The internal consistency of the DSMQ was 0.73.Conclusion: The Thai version of DSMQ showed excellent content validity;good internal consistency.The instruments can be used among Thai adults with DM in future research studies.