Intermittent clamping of the portal pedicle during hepatic resection may reduce the amount of bleeding but it can induce ischemic injury to the liver. Almost all reports about Pringle's maneuver center around the ischemic insult to the liver and the longest duration time. Recently it was reported that prolongation of portal congestion carries a potential risk of serum amylase elevation and pancreatitis after hepatic resection with the intermittent Pringle maneuver. The aim of this prospective study was to analyze the changing patterns of the serum amylase and the lipase levels and to analyze the factors that may be associated with hyperamylasemia and hyperlipasemia after hepatic resection with intermittent Pringle maneuver. The serum amylase and the lipase levels elevated slowly after hepatic resection and reached to the highest level on postoperative day 11. The serum amylase level and the lipase level in the control group was highest on postoperative day 1 and postoperative day 5 respectively. The elevation of the amylase and lipase levels in the major hepatic resection group, the group in which clamping time was more than 30 minutes, and the patient group with normal liver was higher. These results suggest that a prolonged intermittent Pringle's maneuver and the larger amount of resected hepatic parenchyme may cause hyperamylasemia and hyperlipasemia and the underlying mechanism may be the prolonged congestion of the pancreas.