Abstract : There are still limited data about postoperative delirium (POD) in Indonesia. The purpose of this study was to determine the prevalence of delirium in patients undergoing major orthopedic surgeries and understand its related predictors. This was a retrospective cross-sectional study done in an orthopedic hospital with medical record from January 2016 to December 2019. The subjects were over 60 years old who underwent major orthopedic surgeries (arthroplasty, internal fixation, and spine surgery). POD was diagnosed using Diagnostic and Statistical Manual of Mental Disorders (DSM-V). Univariate and Multivariate logistic regression analysis was used to analyze the possible predictors for delirium. Among 201 patients, there were 20 cases (10%) of POD. Multivariate logistic regression analysis indicated that patients with postoperative anemia [OR: 5.189 (1.086– 24.803)], given general anesthesia [OR: 9.194 (1.713 – 49.333)], limited mobility [OR: 17.575 (1.646 – 187.627)], and suffers from sleep disturbance [OR: 35.925 (8.143 – 158.497)] were more likely to develop delirium. POD’s predictor seen in geriatric patients undergoing major orthopedic surgery were mobility restriction, sleep deprivation, postoperative anemia, and general anesthesia. These predictors will help to identify patients with high risk of delirium and could be a potential target for intervention.