Introduction: Endoscopic stenting is currently the treatment of choice for palliative relief of biliary obstruction by a periampullary tumour. If treated surgically, a choledochojejunostomy and Roux-en-Y diversion is still performed by laparotomy in a large number of cases due to technical challenges of the biliodigestive anastomosis in the laparoscopic approach. Robotic systems may enhance dexterity and vision and might therefore support surgeons in delicate laparoscopic interventions. The purpose of this study is to assess the efficacy and safety of performing a laparoscopic choledochojejunostomy and Roux-en-Y reconstruction with the aid of a robotic system. Methods: Ten laparoscopic procedures were performed in pigs with the da Vinci robotic system and compared to ten procedures performed by laparotomy (controls). OR-time, anastomosestime, blood-loss and complications were recorded. Effectiveness of the anastomoses was evaluated by postoperative observation for 14 days and by measuring passage, circumference and number of stitches. Results: OR-time was significantly longer in the robot-assisted group than in the controls (140 vs. 82 min, p<0,05). The anastomoses times were longer in the robot-assisted cases, although not statistically significant (biliodigestive anastomosis 29 vs. 20 min, intestinal anastomosis 30 vs. 15 min, NS). Blood-loss was less than 10 cc in all robot-assisted cases and 30 cc (10-50) in the controls. In both groups, there were no intraoperative complications. In the control group, one pig died of gastroparesis on postoperative day 6. In the robot-assisted group, one pig died on postoperative day 7, caused by a volvulus of the jejunum. At autopsy, a bilioma was found in one pig in the robot-assisted group. In all pigs, the biliodigestive and intestinal anastomoses were macroscopically patent with an adequate passage. Circumference and number of stitches were similar. Conclusion: The safety and efficacy of robot-assisted laparoscopic choledochojejunostomy was proven in this study. The procedure can be performed within an acceptable time frame. Ruurda JP, van Dongen KW, Dries J, Borel Rinkes IHM, Broeders IAMJ. Surg Endosc. In press.