Background Postoperative delirium (POD) is harmful to the prognosis of patients undergoing operation. The non-pharmacological prevention of POD has already been put into clinical practice. The researches of pharmacological prevention of POD, however, are still controversial. Purpose: The aim of this review is to provide a reference to the research and clinical use of pharmacological prevention of POD. Content We summarized the recent researches of pharmacological prevention of POD worldwide, including haloperidol, melatonin, dexmedetomidine, benzodiazepines and cholinesterase inhibitors, and compared their preventive effects on POD. Trend The preventive use of haloperidol, melatonin or dexmedetomidine is significantly effective on POD compared to other medications.