Elderly patients are a high‑risk group for postoperative delirium（POD）, manifested as acute changes in their mental state, involving changes in cognition, attention, and consciousness levels. Many studies have pointed out that sex hormones have a significant impact on brain function, especially in areas such as cognition and memory. The aim of this review is to explore the gender differences of sex hormones in elderly patients, the effects of different sex hormones on brain function and their relationship with POD, and look ahead the application prospect of sex hormone replacement therapy in the prevention and treatment of POD.