Transfusion safety rests on measures ensuring that patients are transfused in accordance with the requirements of state-of-the-art scientific knowledge. This strict attitude is part of a quality approach which now applies to all fields of health. Transfusion is historically characterized by its ambivalence: it was the first medical discipline which integrated Quality Assurance concepts, it was also the first which proved unable to respond adequately in the face of uncontrolled risks. Today transfusion must create a system to rapidly: identify any risk, whether emergent or hypothetical; decide which action should be taken; monitor and assess corrective action; study the medico-economic impact of the whole approach. Quality assurance applies to every stage of the transfusion process, from blood donor to labile blood component recipient. This includes blood donor selection and biological control, labile blood component processing, qualification, transport and conditioning, prescription and distribution of blood components and transfused patient follow-up of. Quality controls, "safety locks", must be implemented at every stage to allow early problem detection, thus avoiding potentially dangerous attitudes and guaranteeing transfusion quality all along the process. Medical prescriptions must follow similar rules and meet Good Practice requirements defined by members of the medical and scientific community. A transfusion should not be prescribed unless it is absolutely necessary. In addition to sanitary surveillance, scientific surveillance must also be implemented to help transferring the findings of fundamental research to transfusion activities and continuously improve transfusion safety. INSERM is initiating sociological studies to identify and better understand donors' attitudes leading to risks. More sensitive tests based on nucleic acid amplification should reduce the incidence of residual viral risks. Various viral cell derivative inactivation techniques are being evaluated: the idea is to remove antigens to suppress the risk of post-transfusion alloimmunization. Numerous R&D; programs address substitution products. Transfusion safety requires all actors in the field of health being equally involved. Putting together experiences and know-how will continuously strengthen the quality approach adopted in transfusion.