Orthotopic liver transplantation is frequently associated with severe bleeding, especially after reperfusion of the grafted liver. Heparin or heparinoids are released from the grafted liver and cause additional blood coagulation disorders. Recently many investigators have used a heparinase guided thromboelastogram (TEG) to control and confirm heparin effects not only on liver transplantation but also cardiac surgery. We reported a clinical case using a heparinase guided TEG to observe the duration of postreperfusion heparin effects.