Hyperglycemia is common following renal transplantation. This study was conducted to evaluate the relationship of perioperative serum glucose levels and acute rejection in 100 nondiabetic patients who underwent renal transplantation. Blood glucose was measured immediately following surgery and every 6 hours during the first 48 hours posttransplant as well as for 1 month to evaluate occurrence of acute rejection episodes (ARE). The rate of ARE was 33%. The mean blood glucose level immediately after surgery in patients with versus without ARE was 249.67 +/- 61.78 and 184.82 +/- 73.35 mg/dL, respectively (P=.000). There was no significant correlation between ARE and donor or recipient age or sex, delayed graft function, type of donor, or treatment. This study suggested a correlation between immediate blood glucose and ARE. In this regard, blood glucose monitoring and control during operation and immediate postoperatively may reduce the acute rejection rate.