We report a case of Budd-Chiari syndrome revealing a polycythemia vera and complicated by heparin-induced thrombocytopenia. A surgical porto-caval shunt was inserted with danaparoid as anticoagulant during the peri-operative period. The doses of danaparoid were as follows: a continuous intravenous infusion of 200 U/h with a target between 0.5 et 0.8 U/ml antifactor Xa activity during the preoperative period, followed by 100 U/h with a target of 0.3 U/ml during the peroperative period; an increase in doses of danaparoid to 150 and 200 U/h with a target above 0.5 U/ml was used during the postoperative period. This case report is a rare situation of hypercoagulable state, in a surgical context, treated with danaparoid.