PURPOSE: There are many openings in the retrohepatic segment of vena cava, and most are variously sized-hepatic veins. The mapping and tracing of these openings may provide an important insight into the clinical anatomy. To date, small hepatic veins had less clinical importance than the major hepatic veins because they have smaller hepatic territories. These smaller veins have obtained greater clinical importance in the practic of a caudate lobectomy for hilar bile duct cancer, and in the splitting of the liver for expanding the donor pool for liver transplantations. METHODS: 3 cm-thick paracaval hepatic segments, including the hepatic hilum and the whole caudate lobe, from thirty-three livers of adult cadavers, were harvested in the central district office of the national office of scientific investigation. The hepatic vein openings in the formalin-fixed tissue were classified as large (LO), medium (MO), small (SM) and minimum (MiO). The internal wall of the retrohepatic segment of the IVC was divided into sixteen areas which were used to record the sites of the openings of the hepatic veins. RESULTS: A total of 537 ostia venae hepaticae were found, with an average of 16.27 per liver. There were 88 LO (16.39%) found, mostly in the uppermost row and the right half of the lower aspect of the wall. There were also 50 MO (9.31%), and 70 SO (13.03%) found, both mostly in the lower parts of the retrohepatic segment of the IVC. There were 329 MiO (61.27%) found scattered extensively throughout the 16 areas. CONCLUSION: The LO were found mostly in the uppermost row, whereas the MO and SO were rather scattered in the middle and lower parts. The MiO occupied 61.3% of the whole ostia, which were scattered diffusely over the entire internal wall of the retrohepatic vena cava. The data from Korean cadavers was more similar to that of the Chinese than the Brazilians.