Recombinant technology in transfusion medicine has really only just begun to have large-scale impact. The preparation of blood products, determination of blood group phenotype, detection of blood group specific antibodies does not currently employ DNA-based methods for their preparation or detection. The detection of blood-borne viruses, production of blood grouping reagents and diagnosis of HLA polymorphism all include recombinant DNA-based technologies and are beginning to impact on routine laboratory life in Transfusion medicine. This review analyses the current use of recombinant technology in transfusion medicine, and indicates where there is likely to be significant development of this methodology (particularly in molecular diagnostics) oven the next decade or so. The impact of molecular medicine in the field of transfusion has already begun. Recent licensing of thrombopoietin for clinical use may have a profound effect on the very high current demand for platelet transfusions. Gene therapy pro tocols for the treatment of haemophilias and other coagulation disorders, and the production of recombinant blood products may reshape the demand for clotting factors from human plasma. I also consider the potential impact of the exciting technologies of DNA arraying and nucleic acid therapeutics in the fields of molecular diagnostics and the possible treatment of leukemia respectively.