Purpose: The evaluation of teaching performance should be multidimensional, and a validated self-evaluation scale is lacking. This study aimed to construct and validate a self-evaluation scale of teaching performance in a medical university. Methods: A 5-dimensional teaching performance framework and an initial pool of 129 items were generated through literature reviews, eight rounds of expert panel discussions, external expert reviews, and a survey with open-ended questions. A pool of 46 items was extracted through the Delphi method and administered to 153 faculty members of a medical university. Item analysis and exploratory factor analysis were performed, and 27 valid items were retained. Results: The 27-item, 5-dimensional scale developed to measure teaching performance in a medical university shows evidence of reliability, validity, and utility for further research. Contrary to our initial conceptualization, the findings reveal that teaching performance comprised five dimensions: 'Clarity of information', 'Facilitation', 'Curriculum planning', 'Enthusiasm', and 'Resource development'. All participants had positive perceptions of their teaching performance, with a mean score of 5.12 out of 6. Female faculty members had significantly higher scores for 'Facilitation' and 'Curriculum planning' than male faculty members. Assistant professors and lecturers had significantly higher scores than professors for 'Resource development'. Conclusions: This study provides a new insight into dimensions and items of teaching behaviour for self-evaluation of teaching performance that would be applied to medical universities. This validated instrument is suitable for medical teachers to self-evaluate their teaching performance.