An interdisciplinary curriculum provides integration of students' subjects and lives, guiding students to understand and engage with changes in the world through real situations and problems, with teachers playing a critical role. However, there is no assessment tool to explore teachers' interdisciplinary role perceptions (TIRP). In this study, an interdisciplinary role perceptions scale for teachers (TIRPS) was developed through literature analysis, expert appropriateness assessment, exploratory and confirmatory factor analysis, and Cronbach's alpha reliability review. The results of the questionnaire were analyzed through importance-performance analysis to understand the current situation of TIRP in Taiwan. First, we found that the TIRPS has good reliability and validity and might be used as a tool for related interdisciplinary research. Second, the importance and performance of "interdisciplinary curriculum development roles" of teachers were well perceived. Third, the performance of teachers in interdisciplinary professional development roles needs to be enhanced with regard to "diagnosing interdisciplinary learning difficulties" and "working with interdisciplinary knowledge." Fourth, teachers identified the need to prioritize the performance of "interdisciplinary multiple-assessment." Finally, this study provides recommendations for the ongoing development of teachers' interdisciplinary role perceptions and meaningful interdisciplinary practices to enhance student well-being.