Further to a survey set up in 2006 over 2600 laboratories by the French agency for health product safety (AFSSAPS), seven ABO grouping errors and 53 negative answers to red blood cell antibody screening with a serum containing anti-RH1 antibody, have been found. A questionnaire sent to the involved laboratories revealed non-analytical errors already met in previous cases. Besides, the analytical stage has also induced red blood cell antibody screening errors due to a wrong serum collection by the automat. Here are displayed the analysis of the questionnaire results and proposed corrections.