Purpose <p>The ARISCAT score can reportedly be used to detect perioperative respiratory complications when they are not predictable by routine pulmonary function tests, blood gas tests, or chest radiography. However, its validity in Japanese patients with hip fractures is unverified. Here, we aim to determine the sensitivity and specificity of the ARISCAT score for the prevalence of respiratory complications in Japanese patients with hip fractures.</p> Methods <p>This study retrospective cohort analysis included patients that underwent surgery for hip fracture at our hospital between July 2020 and March 2022. The primary outcome was the rate of postoperative respiratory issues (pneumothorax, aspiration pneumonia, respiratory infection, bronchospasm, respiratory failure, atelectasis, and pleural effusion).</p> Results <p>Respiratory complications occurred in 17 of 389 patients with hip fractures, with an incidence rate [95% CI] of 4.4% (2.3, 6.4). The mean age was 83.7 [8.7] years, 27.8% were men, and 232 of them (59.6%) had femoral neck fractures. The discriminative power of the ARISCAT score model for the occurrence of respiratory complications was C-statistic 0.71 [0.57,0.83]. Sensitivity and specificity were 52.9% [29.2, 76.7] and 76.8% [72.6, 81.2], respectively, for a score of ≥ 26, and 42.9% [6.2, 79.5] and 96.5% [94.6, 98.4], respectively, for a score of ≥ 45.</p> Conclusion <p>The ARISCAT score had low sensitivity for detecting respiratory complications in Japanese patients with hip fractures. Surveillance of postoperative respiratory complications in Japan should be via regionally validated tools.</p>