BACKGROUND: Well-developed critical thinking skills are required to provide midwifery care that is safe, evidence-based, and woman-centred. A valid, reliable tool to measure is required the application of critical thinking in midwifery practice. The Carter Assessment of Critical Thinking in Midwifery (CACTiM) has previously been psychometrically assessed using classical methods at a single site. This study aims to further evaluate the properties of CACTiM tools using Rasch analysis in a diverse group of midwifery students and preceptors.  METHODS: The CACTiM tools were completed by undergraduate midwifery students studying at three Australian universities and their preceptors. Midwifery students' critical thinking was evaluated separately through student self-assessment and preceptor assessment and then matched. Rasch analysis was used to evaluate the validity of the tools.  RESULTS: Rasch analysis confirmed both the preceptor and student CACTiM tools demonstrated good reliability and unidimensionality. The items can differentiate between students' ability to apply critical thinking in midwifery practice. Person reliability and item reliability were above .92 for both scales indicating excellent reliability and internal consistency. Several improvements were identified to the tools, including enhanced wording to some items, and reduction to a 5-point Likert scale. Through analysis of lower-scoring items, midwifery programs can identify curricula enhancements. CONCLUSION: The CACTiM student and preceptor tools are valid and reliable measures of critical thinking in midwifery practice. The tools can assess students' critical thinking abilities and identify areas for development for individuals and across student cohorts through curricula enhancements.