Advanced cancer of the pancreatic head, especially in its caudal portion, has a limited surgical resectability due to its frequent invasion to the superior mesenteric vein (SMV). A patient with advanced carcinoma of the pancreatic head with vascular invasion to the major bifurcation of the SMV, underwent a pancreatico-duodenectomy under a two-step passive bypass of the portal flow. The marginal colic veins were dilated and formed a long collateral route to the inferior mesenteric vein and the splenic vein due to stenosis of the SMV. The venous flow in this vein was then easily interrupted with the surgical manipulation of the transverse colon. The first passive bypass was thus inserted into the accessory right colic vein to preserve the venous return from both the small intestine and the colon, and also to enable surgical dissection of the invaded SMV itself. After a thorough dissection of the invaded SMV, a second bypass was inserted into the main trunk of the SMV through the dissected vascular stump. Subsequently the passive bypass was maintained until the portal reconstruction with an interposition of the left common iliac vein could be performed. The patient recovered well from the surgery without any complications throughout the postoperative course. In summary, the two-step portal bypass describes, is thus considered a stable and safe procedure for the reconstruction of the superior mesenteric vein, during pancreatoduodenectomy for advanced carcinoma of the pancreatic head.