Three typical cases of segmental portal hypertension due to occlusion of the splenic vein are reported. This syndrome may be asymptomatic for a very long time and then present suddenly in the form of a serious picture of high digestive haemorrhage due to rupture of the varices of the fundus of the stomach as a result of hypertrophized submucous collateral drainage circulation. Useful for diagnosis are oesophagogastroduodenoscopy, which points to stomach varices, and splenoportography or superselective arteriography of the splenic artery with venous phase, which highlight pathognomonic dilatation and tortuosity of the gastroepiploic veins. Surgical exploration typically shows: presence of large epipolic vessels, splenomegaly, absence of changes in the liver and in the portal and mesenteric circulation. Resolutive treatment of choice is splenectomy.