There exists an international consensus on the importance of family-centered care (FCC) in intensive care settings and the evaluation of collaboration between nurses and families; however, FCC is currently practiced blindly in Japan. In this study, we developed a Japanese version of the questionnaire, Factors that Influence Family Engagement (QFIFE-J) and examined its reliability and validity. A web-based survey was conducted with 250 nurses working in the intensive care unit (ICU). Exploratory and validatory factor analyses were used to ascertain factor validity. Criterion-related validity was tested using correlation analysis with the ICU Nurses’ Family Assistance Practice Scale. Internal consistency and reproducibility were verified for reliability. Following exploratory and confirmatory factor analyses, a 15-item measure emerged comprising four factors: “ICU environment”, “nurses’ attitudes”, “nurses’ workflow”, and “patient acuity”. Confirmatory factor analyses showed a generally good fit. Cronbach’s α for the overall scale was 0.78, indicating acceptable internal consistency. The intraclass coefficient for test–retest reliability was 0.80. It was found that the QFIFE-J was reliable and valid and may help determine the factors that promote or inhibit FCC. Additionally, this study has also clarified the current status and family support related issues in ICUs in Japan.