Transfusion of homologous blood to surgical patients is not without risks. Thus, strategies to prevent blood loss must be considered. This article deals with one of them: normovolaemic haemodilution together with its advantages, physiological consequences and technical aspects. In particular, it is important to follow certain inclusion criteria. The technique is safe, effective and relatively easy to implement. In the future, it could be used in non-surgical patients, when it is necessary to increase tissue perfusion.