Blood component therapy aims at satisfying the clinical need of the individual patient without interfering with the general supply of blood products. This aim can be achieved on a common base by applying strict guide lines as regards the use of fresh whole blood, platelet units and coagulation concentrates and increased transfusion of packed red cells and fresh frozen plasma in a reasonable ratio (3:1) instead of whole blood. The current intention of transfusion medicine must be to improve the quality of the blood components in response to the clinical requirements. In this context the production of buffy coat poor erythrocyte concentrates with low viscosity should be generally intended. Beyond this, there are many questions still to be answered dealing with transfusion therapy.