INTRODUCTION: ERCP is an important therapeutic tool in the management of many pancreatico-biliary diseases. Situs inversus viscerum (SIV) is a rare congenital condition characterized by complete transposition of all viscera. We describe our successful ERCP for choledocholithiasis in a patient with SIV. CASE DESCRIPTION/METHODS: A 70 year old female with SIV presented with one day history of severe non radiating epigastric abdominal pain. She had prior similar episodes with fatty meals that resolved without intervention. Initial labs showed total bilirubin of 3.8, ALP 125, AST 1448 and ALT of 1420. A CT scan of the abdomen showed prominent common bile duct. Under general anesthesia, the patient was placed in a prone position. The endoscopist performed the procedure on the left side of the patient. The duodenoscope was passed through the esophagus into the stomach based on landmarks, such as the Z-line and the transition to gastric mucosa. Then, we followed the direction of the gastric folds, allowing the duodenoscope to pass along the surface of the greater curvature. The duodenoscope was advanced to the second part of the duodenum. The major papilla was seen at 6 o clock. The duodenoscope was then rotated counterclockwise 180 degrees. The bile duct was successfully cannulated and ERCP was completed. DISCUSSION: ERCP in situs inversus patient can be challenging. Following anatomic landmarks, appreciation of the congenital abnormality, use of fluoroscopy and vigilant endoscopic maneuvers can aid successful ERCP.Figure 1.: Showing cholangiogram in situs inversus.