Postoperative delirium (POD) is a very common complication in operative disciplines, especially in those elderly patients after cardiac surgery . The described prevalence of POD varies between 30 and 80% in elderly patients after cardiac surgeries [2, 3] and 15%–53% in elderly surgical patients . Numerous studies have revealed that POD is significantly associated with increased complication incidence, long-term cognitive impairment, prolonged hospital length of stay, elevated costs, and overall mortality [5–7]. To predict the implications of POD and improve the quality of care, attempting to determine independent risk factors for POD is of great importance. A number of previous studies have been performed regarding predicative factors for POD; however no consensus has been made until now probably due to the complicated pathogenesis of POD . Previous studies have reported that delirium is associated with elevated proinflammatory cytokines  and proteins involved in the stress response  in medical or surgical patients. C-reactive protein (CRP), one of the most common markers for systemic inflammation, has been indicated as independent risk factor for delirium following vascular surgery  and hip surgery . However, the relationship between CRP and POD in patients undergoing laparoscopic surgery for colon carcinoma still remains relatively unknown, which was just the objective of this present study.