This paper is a report of the psychometric properties of the Thai language versions of the Childbirth Self-Efficacy Inventory and the Childbirth Attitudes Questionnaire, and the equivalence of the Thai and English versions of these instruments.The Childbirth Self-Efficacy Inventory and the Childbirth Attitudes Questionnaire were developed to measure women's abilities to cope with labour and fear of childbirth. Consistent with Bandura's Self-Efficacy Theory, women who have greater confidence in their ability to cope with labour have reported having less fear in childbirth. However, research is needed to validate the measures and this relationship in countries other than the United States of America, where the tools were developed.Back-translation was used. Content validity was examined by experts. The psychometric properties were estimated with internal consistency reliability, construct validity, contrasted groups and criterion-related validity with 148 pregnant women at a hospital in Thailand in 2008.Both measures were shown to have high internal consistency. Contrasting group and criterion-related validity were consistent with self-efficacy theory and findings in the United States. Differences between the stages of labour across expectancies in the Childbirth Self-Efficacy inventory were found only for second stage.Support for good validity and reliability of the instruments when used with Thai women was demonstrated. It may be appropriate for Thai women to use The Childbirth Self-Efficacy Inventory only in relation to the second stage of labour.