Surgical indication and significance of portal vein resection in biliary and pancreatic cancer. Tumor and vascular resection was carried out in 27 patients with biliary and pancreatic cancer. Vascular resection included resection and reconstruction of the both the portal vein and hepatic artery in two of the patients. Portal vein resection only was carried out in 23 patients, and resection of the side wall and plasty of the portal vein was carried out in the other two patients. The technical limit of portal vein resection without graft was 4 cm in the hepatic hilus and 7 cm after total pancreatectomy or pancreatoduodenectomy without grafts. On temporary occlusion of the portal vein between resection and reconstruction, simple occlusion was sufficient if it occurred within 30 minutes. In occlusion of more than 30 minutes, simultaneous occlusion of the superior mesenteric artery is better to prevent congestion of the intestine. If occlusion of more than 60 minutes is anticipated, a bypass between the superior mesenteric vein and the femoral vein with Anthron tube is recommended. The postoperative course was uneventful in 20 of the 27 patients. Two patients died within 1 month after surgery. The mortality rate for this aggressive surgery was 8.4%. Minor complications such as hydrothorax, small bile leakage, and localized abscess were observed but soon subsided in five patients. Fourteen of 27 patients survived or are alive after more than 1 year, and 9 of 14 patients survived or are alive after 2 years. Forty-seven percent of the patients who had no lymph node metastasis or peritumor lymph node metastasis without cancerous invasion of the portal vein intima survived more than 2 years. The longest length of survival of a patient with nonfunctioning islet cell carcinoma of the pancreatic head was 5 years 9 months. The longest surviving patient with ductal cell carcinoma of the pancreas is still living after 4 years. This approach is recommended in certain patients with vascular involvement but without lymph node metastasis or those patients with only peritumor lymph node involvement. Frozen section of mesenteric and paraaortic nodes should be standard practice before this aggressive resection. 