Acute portal vein thrombosis (PVT) is un uncommon disease that can be seen in the Emergency Department. In the emergency department setting the diagnosis is difficult because of the variety of clinical presentation but in some clinical presentation patterns the diagnosis should be suspected. Regard to the appropriate radiological abdominal images, color flow Doppler ultrasonography can diagnose the fresh thrombus and spiral CT may be complementary in the diagnosis. The diagnosis differentiation between acute and chronic portal vein thrombosis is important for therapeutic management and prognosis. In stable patient the most common therapy is heparin and warfarin but in some cases thrombolysis can be the treatment of choice. In the patients with intestinal infarction the surgical therapy is strongly indicated. Two cases , one of acute and the other of chronic PVT, are presented and discussed