Readiness for interprofessional education (IPE) can be an important factor to evaluate because of the influences of attitudes toward the outcomes of interprofessional learning activities. However, a dearth of Japanese evaluation tools hinders its evaluation. The readiness for interprofessional learning scale (RIPLS) was selected, because it has been validated in different countries and its items reflected our local situation best. This research aimed to develop and validate a Japanese version of the original 19-item RIPLS. We developed a Japanese RIPLS employing forward/backward translation. Reliability of the Japanese version was studied using classical test theory and structural equation modeling to construct a model to inform curriculum development. We obtained a 0.74 Cronbach's α, which indicates adequacy. Subscales of "interprofessional education opportunities" (α = 0.90) and "uniqueness of profession" (α = 0.60) have relatively little weight compared to "teamwork and collaboration" (α = 0.92). A one-way structure suggests that readiness for interprofessional learning starts with "teamwork & collaboration" followed by changes in "learning opportunities" and subsequently "uniqueness of profession" (root mean square error of approximation = 0.06, comparative fit index = 0.93). This Japanese RIPLS can be used in undergraduate health sciences students with appropriate caution. Further development of the subscales and a client-centered subscale would be beneficial to fully achieve its potential. The need for further research into its reliability and validity is identified. Recommendations are provided for cross-cultural adaptation and for establishing validity across different contexts.