Intrinsic to pediatrics is the recognition of the ever-changing physiology of the fetus/infant/child and adolescent and the differences and similarities in disease presentation and response to therapy when compared to adults. Although basic, translational and clinical research in adults has aided the treatment of children, clinical discoveries and observations are also made at "the bassinette." These include hemolytic disease of the newborn, transfusion-transmitted HIV and cytomegalovirus, the pathobiology of graft-vs-host disease, use of erythropoietin, consequences of multiple transfusion including alloimmunization and hemochromatosis and the transplantable potential of cord blood, to name just a few. There are recognized challenges to performing clinical research in infants and children, which is guided by the ethical obligation to "first do no harm." New studies in process through multi-institution collaborators will further the field of pediatric transfusion medicine with this ethic as a guiding principle. The future depends on training pediatric physician scientists who will create new knowledge that advances the health and well-being of vulnerable children and youth who require transfusions to support them through complex medical and surgical procedures.