There is a high prevalence of postoperative acute kidney injury (AKI) in patients who undergo intra-abdominal surgery, and it is particularly common in the elderly. Identifying high-risk patients for postoperative AKI early can facilitate the development of preventive and therapeutic management strategies. The goal of this retrospective study is to investigate the predictive value of preoperative nutritional status, as measured by three scoring systems - the geriatric nutritional risk index (GNRI), prognostic nutritional index (PNI), and controlling nutritional status (CONUT) score - on postoperative AKI in elderly patients undergoing major abdominal surgery.