To determine the frequency of factors leading to post endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. Case series. Department of Gastroenterology, Liaquat National Hospital, Karachi, from November 2007 to October 2008. Fifty (50) patients of diagnosed cases of post-ERCP pancreatitis were included in this study. The collected data included age, gender, previous post-ERCP pancreatitis, recurrent pancreatitis, recurrent abdominal pain, number of attempts of common bile duct (CBD) cannulation, difficult CBD cannulation, precut sphincterotomy, biliary sphincterotomy, pancreatic duct contrast injections, primary diagnosis, device used, therapeutic procedure undertaken and the pancreatic enzymes level. Results were described as frequency percentages. Out of 50 patients, 32 (64%) were females. The average age of the patients was 52.23 ± 13.4 years. Frequency of common factors regarding post-ERCP pancreatitis were age ² 60, (n = 38, 76%) patients, female gender (n = 32, 64%), precut sphincterotomy (n = 34, 68%), pancreatic duct contrast injections (n = 27, 54%), biliary sphincterotomy (n = 25, 50%). Higher number of attempts of CBD cannulation and difficult CBD cannulation were recognized as factors for post ERCP pancreatitis. Other factors like previous history, post-ERCP pancreatitis, recurrent pancreatitis, and recurrent abdominal pain were not found in this study. Age, female gender, precut papillotomy, pancreatic duct contrast injections and biliary sphincterotomy were common factors for post-ERCP pancreatitis. Risk stratification will allow endoscopists to better identify patients who are at risk and permit detailed informed consent in high-risk groups or to adapt the measures to prevent the complications and reduce the risk related with the procedure.