Two hundred and sixty-five consecutive patients awaiting hepato-biliary-pancreatic surgery were prospectively observed for surgical site infections (SSIs). SSI rates differed according to type of hepato-biliary-pancreatic surgery. Multivariate analysis identified enteric anastomoses, poor postoperative blood glucose control and type of cancer as independent risk factors. SSI rates were directly correlated with the degree of hyperglycaemia encountered during the postoperative period. In particular, SSI rates were 5/25 (20%) among patients in whom a blood glucose level of <200mg/dL was maintained by insulin infusion therapy, which was significantly better than the rates of 49/94 (52%) among patients in whom a blood glucose level of <200mg/dL was not maintained despite insulin infusion therapy (P<0.01). It is necessary to maintain postoperative blood glucose levels of <200mg/dL in order to reduce SSI rates.