As most of the vascular disorders of the liver are rare and not often encountered by clinicians, the best evidence available has been collected through cohort studies rather than randomized clinical trials. These disorders, although they rarely affect more than 5/10,000 people, are usually focused on the young population and the lack of appropriate disease-specific management could lead to significant morbidity and mortality. The disorders can be differentiated into two groups: those which affect liver inflow, such as non-cirrhotic portal vein thrombosis, the most frequent; and those which involve the liver outflow as the main cause of posthepatic portal hypertension, that is, the Budd–Chiari syndrome and veno-occlusive syndrome. This chapter describes the main features and treatment options of these disorders.