Backgrounds: Hemorrhage, hyperamylasemia and pancreatitis are the major complications of endoscopic sphincterotomy(EST). Although a `blended current'(BC) is usually used for EST to minimize bleeding, a `pure cutting current'(PC) may induce less edema of the ampulla and therefore less injury to the pancreas theoretically. Aim: To evaluate whether the type of electric current affects the development of hemorrhage, hyperamylasemia or clinical pancreatitis after EST. Methods: We reviewed 100 consecutive patients, without coagulopathy, hyperamylasemia, biliary stricture or SO dysfunction, who underwent EST with standard papillotome alone for choledocholithiasis. All EST had performed by one of the two endoscopists whose experiences of EST were similar; one using BC(n=56), while the other using PC (n=44). Hemorrhage was defined as clinical evidence of bleeding and drop in Hb >2 g/dL. Hyperamylasemia was defined as serum amylase >the normal range (30-109 IU/L) at approximately 2 Hr after EST. Clinical pancreatitis was defined as new or worsened abdominal pain and serum amylase >3X the upper normal limit at more than 24 Hr after EST. Results: Baseline clinical, laboratory, and procedural parameters were similar in both groups. The incidence of hemorrhage was not significantly different between the groups (BC 1.8% vs PC 2.3%). The incidence of hyperamylasemia (BC 34% vs PC 32%) and the ratio of post- to pre-EST serum amylase (BC 3.2±.5 times vs PC 2.8±.6 times) were not significantly different. There was also no significant difference in the incidence of clinical pancreatitis between the groups (BC 7.1% vs PC 2.3%; p=0.38 by Fisher's exact test). All episodes of clinical pancreatitis resolved spontaneously within 3 days. Conclusion: Development of complicatons after standard EST such as hemorrhage, hyperamylasemia, and clinical pancreatitis does not seem to depend on the type of electric current used.