The case report of a young female patient with personal history of primary thrombocythaemia, treated with interferon alpha, admitted to our medical department for severe abdominal pain, hepatomegaly, ascites and alteration of hepatic function is presented. Magnetic resonance imaging showed the picture typical for Budd-Chiari syndrome caused by external obstruction of the intrahepatal portion of inferior vena cava. The cause of the syndrome remains uncertain, possibility of the haematogenic infiltration of the liver or venal thrombosis within primary or secondary (interferon - induced) antiphospholipid syndrome is discussed. Liver biopsy could elucidate the exact cause, but it was not performed for technical problems.

        Key words: Budd-Chiari syndrome, primary thrombocythaemia, interferon alpha, antiphospholipid syndrome, infiltration of organs, TIPS.