Abstract Background: Post-Endoscopic retrograde cholangiopan-creatography [ERCP] pancreatitis is one of the most frequent and feared complications following ERCP and can lead to significant morbidity as well as occasional mortality. Endo-scopic sphincterotomy is a procedure of ERCP that is either used solely for the treatment of diseases of the papilla of Vater, such as sphincter of Oddi dysfunction or to facilitate subsequent therapeutic biliary interventions such as stone extraction or stenting and decrease the possible. Aim of Study: To evaluated the effect of sphinctrotomy in reducing or increasing post ERCP pancreatits. Patients and Methods: A prospective cohort study was conducted in General surgery, Gastro-enterology and Hepa-tology Department Faculty of Medicine, Assiut University Hospital on 100 patients aged from 15 to 70 years from both sexeligible for ERCP for extraction of common bile duct stones, treatment of papillary stenosis and facilitation of endotherapy [i.e. stent placement, tissue sampling and stricture dilation] allocated into 2 equall groups [50 patients each]; group A, in which ERCP was performed with cannulation of the common bile duct and group B in which ERCP was performed with sphincterotomy. Pre-operative assessment included full history, physical examination, serum amylase and lipase and pelvi-abdominal ultrasound. Results: There were no statistically significant differences between both groups as regarding postoperative ultrasound findings and post-operative results of laboratory investigations including: Lipase and amylase. Conclusion: Sphincterotomy can be performed safely and effectively during ERCP without fear of an increased risk of post-ERCP pancreatitis.