Objective To investigate the value of timely duodenal papilla fenestration for reducing the incidence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP).Methods The clinical data of 181 patients with difficult biliary cannulatian during ERCP at the Xinhua Hospital of Shanghai Jiaotong University from July 2006 to December 2009 were retrospectively analyzed.Of the 181 patients,98 patients who received traditional incubation were in the control group,and the other 83 patients who received early duodenal papilla fenestration were in the test group.The success rate of selective incubation and incidence of pancreatitis were compared between the 2 groups.All data were analyzed using the t test,chi-square test or Wilcoxon rank sum test.Results The success rate of incubation,incidences of hyperamylasemia and pancreatitis were 85.7％ ( 84/98 ),7.1％ (7/98) and 10.2％ ( 10/98 ) in the control group,and 94.0％ ( 78/83 ),18.1％ ( 15/83 ) and 2.4％ (2/83) in the test group,respectively,and there were significant differences between the 2 groups (x2 =10.12,5.03,4.41,P＜0.05).The numbers of patients with mild,moderate and severe pancreatitis were 3,5 and 2 in the control group,and 1,1,0 in the test group,respectively,and there was a significant difference between the 2 groups ( Z =- 2.11,P ＜ 0.05 ).Conclusion Timely duodenal papilla fenestration is safe and effective in reducing the incidence of pancreatitis for patients with difficult biliary cannulation during ERCP.