As the population ages, the number of elderly patients who choose to undergo surgical procedures is gradually increasing, but the incidence of postoperative delirium in elderly patients is gradually increasing due to their physiological changes, preoperative malnutrition, and prolonged preoperative fasting. The role of preoperative carbohydrates as a contemporary element of the rapid recovery surgery (ERAS) paradigm in preventing the onset of postoperative delirium has become a clinical research hotspot. A full understanding of the safety and feasibility of preoperative oral carbohydrates for elderly patients will help to reduce the incidence of postoperative delirium and promote early recovery of elderly patients. This paper presents a review of the effects of preoperative oral carbohydrates on POD in elderly patients.