The French Blood Agency has developed a national system of surveillance and alert, from blood collection to the follow-up of the recipients, called haemovigilance. The French haemovigilance network is now operational, and aims at detecting, gathering and analysing unexpected or undesirable effects associated with transfusion in order to remedy their causes and prevent their recurrence. Thanks to 1) traceability of blood products from donors to recipients, 2) spontaneous reports of transfusion adverse events, and 3) rigorous management of information related to the transfusion process, haemovigilance effectively contributes to blood transfusion safety.