ABSTRACT In this study, we developed and validated the Clinical Student Version of the Japanese Interprofessional Competency Self-Assessment Scale (C-JASSIC) for healthcare students in their clinical practice phase. Data obtained from 331 students (medical, 98; nursing, 99; pharmacy, 134) during orientation for interprofessional education (pre-IPE) and from 319 students (medical, 94; nursing, 93; pharmacy, 132) within a week following IPE (post-IPE) were analyzed. Exploratory pre-IPE and Confirmatory post-IPE factor analyses revealed a consistent 6-factor structure aligning with the Japanese Interprofessional Competency domains. The scale exhibited strong internal consistency, with Cronbach’s α values exceeding 0.8 for all factors both pre- and post-IPE. Scores for overall competency and individual domains increased post-IPE in 234 matched cases. A notable significant pre vs post difference concerned “Understanding of Others,” indicating enhanced interprofessional comprehension after clinical practice. There was a weak but significant positive correlation between IPE satisfaction and difference in pre- and post-IPE scores. However, no significant differences were observed among medical, nursing, and pharmacy students. Despite its strengths, such as its competency-based design and cultural relevance to Japan, a limitation of the study may be potential self-reporting bias. Nonetheless, C-JASSIC represents a valuable tool for seamless competency evaluations from student to professional stages, with implications for broader Asian contexts.