The portal venous thrombosis is an infrequent disease that accounts from 0.25 to 1%. The etiopathogenesis is unknown in about one half of cases. Sometimes the thrombosis of mesenterico-portal venous axis is a complication following splenectomy, especially when the operation is performed for hematologic disease. The authors report a clinical case of chronic portal venous thrombosis widespread to superior mesenteric and splenic vein, in man 38 years old after splenectomy, in pediatric age, manifesting with gastrointestinal bleeding due to rupture of esophagogastric varices. On the basis of literature, the following were taken into consideration the incidence, the epidemiology, the aetiopathogenesis, the clinical characteristics, the diagnosis as well as the therapy of portal venous thrombosis.