In several clinical situations, including resection of malignant or benign biliary lesions, reconstruction of the biliary system using the Roux-en-Y jejunum limb has been adopted as the standard procedure. The basic technique and the procedural knowledge essential for most gastroenterological surgeons are described in this article, along with a video supplement. Low complication rates involving anastomotic insufficiency or stricture can be achieved by using proper surgical techniques, even following small bile duct reconstruction. Using the ropeway method to stabilize the bile duct and jejunal limb allows precise mucosa-to-mucosa anastomosis with interrupted sutures of the posterior row of the anastomosis. Placement of a transanastomotic stent tube is the second step. The final step involves suturing the anterior row of the anastomosis. In contrast to the lower extrahepatic bile duct, the wall of the hilar or intrahepatic bile duct can be recognized within the fibrous connective tissue in the Glissonean pedicle. The portal side of the duct should be selected for the posterior wall during anastomosis owing to its thickness. Meticulous inspection to avoid overlooking small bile ducts could decrease the chance of postoperative intractable bile leakage. In reconstruction of small or fragile branches, a transanastomotic stent tube could work as an anchor for the anastomosis.