Postoperative delirium (POD) is an acute neuropsychiatric syndrome characterized by attention deficit and cognitive dysfunction after surgery, and commonly seen in elderly patients. It is known that aging, surgical anesthesia and sleep disorders are related to the occurrence of POD, and one of the mechanisms may be blood‑brain‑barrier (BBB) damage. This paper summarized the role of BBB damage in the occurrence and development of POD in the recent years, and discusses the detection of BBB damage markers related to POD, so as to provide new ideas for clinical diagnosis, prevention and treatment of POD.