During the last years, the use of hemoderivatives has largely increased. Their use carries a high risk for post-transfusion reactions and for transmission of severe infectious diseases. In a high percentage of cases the use of these compounds is inadequate. At the present time there are pharmacologic (desmopressin, antifibrinolytics, vitamin K) and nonpharmacologic strategies (autotransfusion, hemodilution, intra and postoperative recovery of blood) directed to avoid or to decrease the need for transfusion. We review all these strategies and we propose some criteria for transfusion of plasma and platelets, as well as attitudes for particular situations.