To determinate the characteristics of the segment V in the liver, we studied the intrahepatic vascular structure of 200 human livers taken from necropsies of males and females of different ages, from fetuses to octogenarians, all races. 150 livers were injected with acrylic in the portal vein, hepatic artery, biliary ducts, inferior cava vein and hepatic veins. We dissected 50 livers based on the knowledge obtained from the acrylic injected livers. We found that the segment V has only one branch, the largest of the seven portal segmental branches. After penetrates 2 cm in the hepatic parenchyma gives anterior branches, lateral branches, posterior branches and medial branches. This segmentary branch emerged from the right portal vein in 80% of cases and from the left portal vein in 20%.