We present definitions and proposals in relation to the anatomy of the liver based on our investigation using dissection, acrylic injection, tomographic and radiological studies of 286 human livers of sexes, different races and ages ranging from fetuses to octogenarians. We define: 1) Portal segment, 2) Portal pedicle, segmental pedicle, 3) Portal fissures, 4) Porta Hepatis or Lower hepatic hilum, 5) Groups of hepatic return veins, 6) Left hepatic vein pathway and 7) Aberrant bile duct. We propose: 1) Segment V only formant of the right medial division, 2) Seven terminal segmental portal branches, 3) Segmental arterial irrigation, 4) Formation of bile ducts, 5) Change the denomination of main portal fissure by intermediate portal fissure, 6) Include within the concept “umbilical fissure” the fissure of the round ligament and fissure of the venous ligament, 7) Horizontal portal fissures, 8) Veins that drain in the inferior vena Cava, 9) Do not call the posterior portion of the liver (A05.8.01.043) to the caudate lobe.