The principal descriptions of the portal vein are mainly on the results of the dissections of the corpses. The aim of the work was to determine the usual sizes of the portal vein on the alive subject by echography. From the same machine, 3 ultrasonographers studied the anatomy of the portal vein of the volunteers according to a standardized methodology. The study was about 60 old people from 11 to 82 years old, whom 31 were males (51.7%) and 29 females (48.3%). The transverse diameter of the portal vein, originally varied between 8 and 10 mms un 57.9% of cases. The average was 9.05 mms +/- 2.82 and the extremes varied from 5 to 16 mm. The transverse diameter of the portal vein, at the end varied between 8 and 10 mms. The average was 9.16 mms +/- 2.58 and the extremes varied between 6 and 16 mms. In 29.8% of cases, the length of the portal vein was between 61 and 70 mms and in 8.8% between 81 and 100 mms. The average was 58.0 +/- 22.3 mms. Before its entry into the liver, the portal vein is divided into 3 branches in 2 cases (3.3%). The study showed a significant change of the length of the portal vein according the age and sex.