The origin of blood loss during liver surgery is multifactorial. Surgical skill, technique, anesthesiological care, but also hyperfibrinolysis have been shown to play a role in the origin of bleeding during partial hepatectomy and liver transplantation. The latter has provided the scientific basis for the prophylactic use of antifibrinolytic drugs, such as aprotinin and nafamostat mesilate in liver surgery. Recently however, concern has been voiced about potential risks associated with aprotinin, including renal failure and thromboembolic events. In this review we discuss the efficacy and safety issues of aprotinin and nafamostat mesilate in liver surgery. We identified a total of 19 studies on the use of either aprotinin or nafamostat mesilate in liver surgery reported in the time period between 1966 and July 2006. The use of aprotinin or nafamostat mesilate in partial hepatectomies was studied in three studies. In 16 studies the use of aprotinin in liver transplantation was investigated. With respect to partial hepatectomy, improvements in surgical technique and anesthesiological care seem to be more important in reducing blood loss than the use of the antifibrinolytic drugs. Aprotinin may be indicated in a selected group of patients with cirrhosis undergoing liver resection, but further studies in this specific group of patients will be needed. In liver transplantation, the use of aprotinin is associated with a significant reduction in blood loss and transfusion requirements of around 30-40%. Results of prospective studies do not provide support for safety concerns as no increased risk for thromboembolic events or renal dysfunction has been observed in liver transplant patients treated with aprotinin. In conclusion, there is currently no scientific support for the routine use of aprotinin or nafamostat mesilate in patients undergoing partial hepatectomy, whereas the efficacy of aprotinin in liver transplantation is well established. More studies will be needed to address the safety aspects of aprotinin in patients undergoing liver surgery in more detail.