We report successful treatment of acute severe Budd-Chiari syndrome with portal venous thrombosis. The prognosis of patients with this condition is poor, because the therapeutic options are limited. A 38-year-old woman with polycythemia vera was admitted in a critical condition, and Budd-Chiari syndrome complicated by portal venous thrombosis was diagnosed. Tissue plasminogen activator and urokinase were infused systemically and were partially effective. Transjugular intrahepatic portosystemic shunting to reduce the high portal venous pressure was performed successfully and, eventually, her general condition improved. Our experience indicates that emergency transjugular intrahepatic portosystemic shunting is an effective therapeutic modality for controlling portal hypertension in patients with severe Budd-Chiari syndrome with portal venous thrombosis.