Objective: To evaluate the reliability and validity of this new measure, called the caregivers’ fear of falling index (CFFI). Methods: The study surveyed home-based rehabilitation patients with fall-related fracture, and their primary caregivers. The characteristics of these patients were evaluated, and the caregivers were surveyed using the CFFI and Falls Efficacy Scale-International (FES-I). The reliability of the CFFI was assessed using item-total correlation, while the validity of the CFFI was evaluated through correlation coefficients calculated between the CFFI and the FES-I. Results: The participants were 51 patient-caregiver pairs. The internal consistency of the CFFI showed an alpha coefficient of 0.904. No items were excluded in the corrected item-total correlations. The CFFI showed a moderate correlation with FES-I (r=0.432, p=0.002). Conclusion This study found the CFFI to be a reliable and valid tool for measuring the primary caregivers’ fear. The CFFI may be a useful tool for healthcare professionals to identify and supporting these primary caregivers.