Objective To evaluate the effectiveness and safety of pancreatic duct stenting in prevention of post-ERCP (endoscopic retrograde cholangiopancreatography) pancreatitis for patients at high risk. Methods We searched the Controlled Trials Database of the Cochrane Upper Gastro-Intestinal and Pancreatic Disease Group (Issue 1, 2004), Cochrane Controlled Trials Register (Issue 1, 2004), MEDLINE (1966-2004, 4), EMBASE (1985-2004, 4), CBMdisk (1970-2004, 4), and the Chinese Cochrane Center Database of Clinical Trials; we handsearched 8 Chinese journals, and references of eligible studies were also screened for inclusion. Randomized controlled trials on pancreatic stent for preventing post-endoscopic restrograde cholangiopancreatography pancreatitis (PEP) were identified.The systematic review was conducted using methods recommended by the Cochrane Collaboration. Results Six trials involving 468 high-risk patients for post-ERCP pancreatitis were included. The incidence of post-ERCP pancreatitis was significantly reduced by pancreatic duct stenting (Peto RR 0.31, 95% CI 0.19 to 0.52; P＜0.000 01; NNT=6). The incidence of severe PEP was also significantly lower in pancreatic duct stenting group compared with the control group (Peto OR 0.13, 95% CI 0.04 to 0.47; P=0.002; NNT=24). The results were consistent with the sensitivity-analysis when abstracts were excluded. Conclusion Pancreatic duct stenting appears to be an effective method to prevent PEP. Due to the limitation of the included trials and their methodology, the results should be considered with caution. High quality and large-scale trials are required.