Purpose: To examine the reliability and validity of the Camouflaging Autistic Traits Questionnaire–Japanese version (CAT-Q-J). Methods: Self-report questionnaires were administered to 204 adults with and 410 adults without autism. Test–retest reliability was confirmed via another survey administered after two weeks.Results: The overall CAT-Q-J showed good reliability, correlating approximately with other scales, supporting its convergent validity. However, a few subscales had insufficient reliability and validity. Exploratory factor analyses showed three factors similar to the original in non-autistic sample (plus a factor comprising reversed items). For the autistic sample, three factors partially differed from the original. Conclusion: Despite acceptable consistency, reliability, and validity at an overall level, the CAT-Q-J should be used with caution.
