Background: Fall risk assessment and preventive interventions are important for preventing secondary fractures after hip fracture. The aim of this study was to investigate the distribution and characteristics of Fall Risk Index-21 (FRI-21) scores based on prefracture living conditions in patients with fall-related unilateral hip fracture. Methods: This study included 95 people who had suffered a hip fracture after a fall and had undergone surgery. FRI-21, dual energy X-ray absorptiometry (DXA), and hip structure analysis/trabecular bone score based on DXA were performed within 1 week after surgery. We compared bone parameters between the two groups, which were divided according to the cutoff value of the FRI-21. We also performed cluster analysis on the components of the FRI-21 and compared the characteristics of the subgroups via analysis of variance and multiple comparison tests. Results: All participants had experienced a fall-related fracture, but 47 (49.5%) of the patients were judged to have low scores (<10) on the FRI-21. Moreover, cluster analysis revealed that the subjects were classified into three subgroups, and the characteristics of the items that constitute fall risk, namely, physical function, disease or geriatric syndrome, and environmental factors, were diverse. Conclusions These results suggest that caution is needed when interpreting the FRI-21 total score based on preoperative living conditions in post-fracture patients, as it may not adequately reflect fall risk. Considering the characteristics of the FRI-21 score in patients with hip fractures, identifying appropriate fall prevention strategies and healthcare professionals involved may be important for preventing future re-fractures.