Surgical resection is currently the primary option for long-term survival in extrahepatic bile duct cancer. In patients undergoing resection, R0 resection is the most favorable prognostic factor. Surgeons routinely evaluate the proximal and distal margin through frozen section and if invasive cancer was present, further resection would be performed if technically or anatomically permissive. However, it remains controversial that further resection is oncologically beneficial. In addition, the accuracy of the frozen section interpretation is unclear. In this regard, if the margin status is high grade dysplasia (HGD), should we perform further resection? Surgeons who favor further resection may insist that R0 is the principle of surgical oncology. However, not all cancer surgeries can adopt this principle because aggressive cancers such as pancreatic cancer has no definite evidence of survival gain after further resection. Surgeons who favor further resection may insist residual HGD have higher risk of local recurrence that can lead to poorer survival. However, advanced stage cancer usually recur systemically that local recurrence may not affect the patients’ survival. In addition, if further resection of the bile duct needs major hepatectomy, e.g. hepatopancreatoduodenectomy (HPD), it increases the morbidity and mortality rate. Especially in elderly patients, HPD has higher risk of postoperative mortality. To avoid liver resection, surgeons can try further bile duct resection. However, even we can obtain R0 after further bile duct resection, it must be very hard to make a safe anastomosis because of the small caliber of the bile duct, which may result in bile leakage or even anastomosis dehiscence. Postoperative complication may result in delayed adjuvant therapy, which may play a negative impact on the survival of this disease. Sometimes it may be impossible to start an adjuvant therapy because of the poor performance status of the patients after recovery of the severe complications.