Background: Patients with diabetes have an increased risk for allograft rejection, possibly related to peri-operative hyperglycaemia. Hyperglycaemia is also common following transplantation in patients without diabetes. We hypothesise that exposure of allograft tissue to hyperglycaemia could influence the risk for rejection in any patient with high sugars. To investigate the relationship of peri-operative glucose control to acute rejection in renal transplant patients without diabetes, all patients receiving their first cadaveric graft in a single center were surveyed and patients without diabetes receiving cyclosporin-based immunosuppression were reviewed (n = 230). Records of the plasma blood glucose concentration following surgery and transplant variables pertaining to allograft rejection were obtained. All variables suggestive of association were entered into multivariate logistic regression analysis, their significance analysed and modeled. Results: Hyperglycaemia (>8.0 mmol/L) occurs in over 73% of non-diabetic patients following surgery. Glycaemic control immediately following renal transplantation independently predicted acute rejection (Odds ratio=1.08). 42% of patients with a glucose < 8.0 mmol/L following surgery developed rejection compared to 71% of patients who had a serum glucose above this level. Hyperglycaemia was not associated with any delay of graft function. Conclusion: Hyperglycaemia is associated with an increased risk for allograft rejection. This is consistent with similar findings in patients with diabetes. We hypothesise a causal link concordant with epidemiological and in vitro evidence and propose further clinical research.