BACKGORUND: Venovenous bypass (VVB) in liver transplantation has been used to decrease the acute hemodynamic and metabolic changes during anhepatic periods. But, the use of VVB in patients undergoing liver transplantation is still under debate concerning its relative risks and benefits. Therefore, the aim of this study was to examine the influences of VVB on the coagulation status and the amount of transfusion in living-related liver transplantation. METHODS: We conducted this retrospective study on 39 patients who underwent orthotopic living-related liver transplantation using the piggyback technique from March 2001 to April 2002. While 19 patients did not receive venovenous bypass, 20 patients received. We compared the two groups in terms of coagulation-related parameters (prothrombin time, activated partial thromboplastin time, platelet count, fibrinogen and thromboelastograph), the amount of transfusion during intraoperative and post-operative 1day. We also compared the incidences of post-reperfusion syndrome in the two groups. RESULTS: The group that underwent living-related liver transplantation with VVB required more packed red blood cell (p-RBC) transfusion than the other group without VVB from post-reperfusion untill the end of operation (P<0.05). This difference in the amount of p-RBC transfusion may be due to the blood remained in the VVB circuit at the termination of VVB. However, the two groups were similar in terms of coagulation-related parameters, the amount of other blood components, such as fresh frozen plasma, platelet concentrates, cryoprecipitate, total amount of transfusion during the 24 hours post- operatively, and the incidence of post-reperfusion syndrome. CONCLUSiONS: We conclude that the using of venovenous bypass in living-related liver transplantation did not influence coagulation status and the amount of transfusion perioperatively.