Despite the increased safety of allogeneic blood products, adverse effects such as transfusion reactions, increased infections, and possible immunosuppressive effects have contributed to the demand for alternative techniques, the so-called "blood saving techniques", which also may have adverse reactions. Retrospective studies with aprotinin underscore the importance of controlled randomized trials or cohort studies large enough to detect the incidence of these adverse effects or differences in side effects with allogeneic blood transfusions. The safety of aprotinin is currently under debate and the drug has been withdrawn from the market. Tranexamic acid, on the other hand, is a safe and potent drug, and is approximately as effective as aprotinin. No data are available thus far to contraindicate its use in liver surgery, in contrast to macroscopic haematuria. Thus, tranexamic acid appears to currently be the safest antifibrinolytic product. Copyright © 2008, Nederlandse Vereniging voor Intensive Care. All Rights Reserved.