Budd-Chiari syndrome is a rare disorder characterized by obstruction of hepatic venous outflow involving either the hepatic veins or the inferior vena cava. Risk factors include thrombophilia and myeloproliferative disorders, and symptoms are often unspecific. We present a case of a 60-year-old woman admitted to our medical unit for ascites and abdominal pain. Although her medical history significant for a mixed connective tissue disease and a mild increase of the transaminases had raised the suspicion of autoimmune hepatitis, the demonstration on computed tomography of the absence of outflow in the terminal tract of the supra-hepatic veins allowed a correct diagnosis. The contribution of radiological imaging is fundamental in the diagnosis of this rare and elusive pathology.