Portal or/and mesenteric vein thrombosis is a rare condition with high mortality in an acute form. Therapy of thrombosis is not well defined, although there are some general guidelines that differ according to disease onset and clinical presentation. In acute thrombosis with bowel infarction, surgical resection with possible thrombolysis is advised. The best therapy for the subacute form is not known and the approach differs between centers. For chronic disease, prolonged anticoagulant therapy is recommended. Thrombolysis is well recognized in the treatment of acute ischemic coronary or cerebral diseases. Success of treatment is better if therapy is introduced within a few hours after symptoms have begun. We describe a 25-year-old patient with the subacute form of extensive portal, mesenteric and ileocolic vein thrombosis in the setting of underlying liver cirrhosis due to autoimmune disease. An aggressive therapeutic approach is advised, especially in patients who will eventually undergo liver transplantation, since portal and/or mesenteric vein thrombosis is relative contraindication for liver transplantation in the majority of transplant centers.