BACKGROUND Laparoscopic gastric bypass is one of the most performed bariatric operations worldwide. The exclusion of stomach and duodenum after this operation makes the access to the biliary tree, in order to perform an endoscopic retrograde cholangiopancreatography (ERCP), very difficult. This procedure could be more often required than in overall population due to the increased incidence of gallstones after bariatric operations. Among the different techniques proposed to overcome this drawback, laparoscopic access to the excluded stomach has been described by many authors with a high rate of success reported. METHODS We herein describe our technique to perform laparoscopic transgastric ERCP. A gastrotomy on the excluded stomach is performed to introduce a 15-mm trocar. Two stitches are passed through the abdominal wall and placed at the two sides of the gastrotomy for traction. The intragastric trocar is used to pass a side-viewing endoscope to access the biliary tree. CONCLUSIONS In patients with a past history of Roux-en-Y gastric bypass (RYGB), the present technique allows us a standardized, safe, and reproducible access to the major papilla and the biliary tree using a transgastric access. This will lead to simplify the procedure and reduce the risk of peritoneal contamination.