Background and aim: Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard for the treatment of the biliary and pancreatic diseases. Post-ERCP complications are inconsistent and sometimes have insufficient patients’ follow-up. The aim of this study was to determine the outcomes of performing ERCP and compare these with published figures. Methodology: A prospective single-center study was conducted to evaluate the ERCP procedure on 155 consecutive patients during a period of 12 months. All ERCPs were therapeutic procedures or performed with therapeutic intent at Taleghani Hospital in Tehran, Iran. Data on the patients’ characteristics, ERCP indications and findings during the procedure and after that as complications were collected. All results and complications were recorded simultaneously and entered into the database. Results: Total of 155 procedures was performed. Bile duct cannulation rate was 92.3% and therapeutic success rate was 88.5%. Complications occurred in 18.7% of patients and ERCP specific mortality was 1.3%. The most common complications were mild pancreatitis (7.7%), followed by cholangitis (7.1%), perforation (1.3%), and bleeding (1.3%). Choledocholithais was more common in patients with post-ERCP complications (P=0.01). Female gender, young age (≤ 65 years), periampullary diverticulum, suspected sphincter of Oddi dysfunction (SOD), bile duct stent placement were not found to be risk factors for overall complications. Multivariate analysis showed a choledocholithais and PD guidewire entrance as independent risk factors for overall complications (P < 0.05). Conclusion: Despite its associated morbidity and risk of mortality, ERCP is an important method for managing the pancreatico-biliary diseases. Our indications, interventions, and complications rates as well as risk factors were comparable to those reported in other countries.