Endoscopic retrograde cholangiopancreatography (ERCP) has become an important tool in the diagnosis and treatment of pancreaticobiliary pathology. ERCP in patients that have undergone Roux-en-Y gastric bypass (RYGB) is particularly challenging because traditional transoral endoscopy may be limited. We present our experience with ERCP after RYGB and review the literature. In 2007 eight patients underwent ERCP after RYGB using open or laparoscopic transgastric access. After introduction of pneumoperitoneum, a total of four ports were placed. A purse-string was placed around a gastrotomy 4 to 6cm proximal to the pylorus. The endoscope was introduced through a 15 mm left-upper-quadrant port and the gastrotomy. Endoscopy was then performed. Laparoscopic gastrotomy was used in all patients that underwent a previous laparoscopic Roux-en-Y gastric bypass (LRYGB) (n = 6) and open gastrotomy was used for patients with a previous open RYGB (n = 2). Cannulation and interventions in the pancreaticobiliary tree were successful in all cases. There were no postoperative complications. Laparoscopic transgastric ERCP after LRYGB is feasible, highly successful, may be performed expeditiously, and does not seem to add significant morbidity to the procedure. The ability to perform ERCP in this patient population is critical due to their tendency to have preexisting biliary disease and to develop gallstones and the associated complications.