The need to adapt red blood cells concentrates management in surgery blocs and resuscitation to the changes of the legal framework has lead to a collective approach to improve practices. Gathered by the regional hemovigilance coordinators of the Drass Ile-de-France (regional office of health and social actions), representatives of doctors' ordering transfusions and hemovigilance correspondents of the Assistance publique-Hôpitaux de Paris and representatives of the EFS (French blood establishment) Ile-de-France, together with representatives of the Afssaps (French health products safety agency), have coordinated an assessment of local transfusion practices in surgery blocs and resuscitation that have to be compliant. Each hospital then offered local improvement actions, approved by regional and national instances. We present this original and collective approach of assessing practices leading to offers that both respond to a legal framework and improve blood products flows without damaging transfusion security.