Background: Improving individuals' experience of care is now a critical goal of health care systems. Although a number of instruments have been developed to measure experience of care, few instruments measure family caregivers' experience of interprofessional care for patients and families.Objective: To develop the Japanese version of the Caregivers' Experience Instrument (J-IEXPAC CAREGIVERS) and to investigate its validity in assessing quality of integrated care for both patients with chronic conditions and their family caregivers, from the caregivers' perspective, in Japan. Methods: We used a cross-sectional questionnaire survey to test the validity and internal consistency of J-IEXPAC CAREGIVERS. Four hundred family caregivers were recruited in three municipalities. We evaluated the feasibility, structural validity, internal consistency and hypothesis testing for construct validity of the scale. Results: A total of 274 (68.5%) questionnaires were analysed. Confirmatory factor analysis showed acceptable model fit for the hypothesized two-factor model according to fit indices, as identified for the original version: attention for the patient and attention for the caregiver. Cronbach's alpha for score in J-IEXPAC CAREGIVERS with 12 items was high (0.92). Spearman's rank correlation coefficient between overall caregiver satisfaction and J-IEXPAC CAREGIVERS score was 0.71. Family caregivers who experienced home-visit services had significantly (P = 0.001) higher total scores than those who did not. Conclusions: This pilot study showed that the J-IEXPAC CAREGIVERS is valid and reliable. This scale can be useful for evaluating quality of integrated care, with focus on family caregivers and patients with chronic conditions in Japan.