We reviewed the intraoperative plasma glucose concentrations in 100 consecutive patients who underwent orthotopic liver transplantation. The plasma glucose concentration increased significantly (P less than 0.05) from 110 +/- 46 mg/dl (mean +/- SD) to 204 +/- 60 mg/dl during the preanhepatic phase of transplantation (phase I). No significant change in plasma glucose concentrations occurred during the anhepatic phase (phase II). During the reperfusion phase (phase III), the mean plasma glucose concentration increased significantly (P less than 0.05) from 201 +/- 56 mg/dl to 384 +/- 72 mg/dl. The only glucose administered was that contained in the blood products. No correlation was found between the amount of glucose administered with the blood products and the changes in plasma glucose concentrations in these patients. None of the patients became hypoglycemic during any phase of the transplant procedure. All patients demonstrated a tendency toward hyperglycemia.