Postoperative cognitive dysfunction is related with the use of opioids in the postoperative period, lack of physical activity, fatigue, postoperative pain and quality of life. The use of corticosteroids preoperatively reduces postoperative pain, fatigue, nausea and vomiting in the postoperative period and is frequently used as an adjuvant in anesthesia. This study aims to evaluate the possible effect of dexamethasone on prevention of cognitive dysfunction in the postoperative period of elderly patients undergoing to surgery under general anesthesia.