Background The purpose of this study is to investigate whether the preoperative comprehensive geriatric assessment (CGA) would predict postoperative delirium (POD) in elderly patients with hip fracture. Methods This is an observational study, performed in a tertiary hospital from June 2014 to May 2018, which enrolled patients with hip fracture aged over 65 years. The comprehensive geriatric assessment for recruited patients was carried out before surgery. POD was recorded prospectively until discharge. Delirium was diagnosed according to the Confusion Assessment Method (CAM) algorithm. Results POD occurred in 22.09% of the 507 patients who underwent hip surgery. The Barthel index, Mini-Mental State Examination (MMSE), instrumental activities of daily living (IADL), vitality index, and Geriatric Depression Scale (GDS) results were related to the occurrence of POD. All of them were independent factors related to the occurrence of POD after adjusting other traditional risk factors. Conclusions The comprehensive geriatric assessment before hip fracture surgery can predict the occurrence of POD in elderly patients.