Objective To analyze the risk factors for postoperative cognitive confusion in a surgical intensive care unit. Methods A total of 388 consecutive patients in Surgical Intensive Care Unit of General Hospital of PLA were retrospectively studied. We posed clinical questions according to the patients with older age and large dosage corticosteroid. Using “Postoperative cognitive confusion” and“Intensive Care” as key words, we searched for evidence from MEDLINE (1968-2004). Results We found 3.1% (10/388) of the patients developed postoperative cognitive confusion. Of the 10 postoperative cognitive confusion patients, 9 were over 65 years old. 6.6% (9/136) of the patients (≥ 65 years old) developed postoperative cognitive confusion. While 0.4%(1/252) of the patients (＜65 years old) developed postoperative cognitive confusion. Older age (≥ 65 years old) may induce more postoperative cognitive confusion (P＜0.05). While 7.0% (5/71) of the patients treated by large dose corticosteroids (≥1 000 mg) developed postoperative cognitive confusion. And 1.65% (5/317) of the patients received corticosteroid with large dosage (＜1 000 mg) developed postoperative cognitive confusion. Large dosage corticosteroid (≥1 000 mg) may induce more postoperative cognitive confusion (P＜0.05). Conclusion Older age (≥ 65 years old) and high dose corticosteroid (≥1 000 mg) may be the two main risk factors for postoperative cognitive confusion.