Chagas disease or American human trypanosomiasis, is a parasitic disease due to Trypanosoma cruzi, which is endemic in Latin America. The parasite is transmitted by haematophagous vectors from reduviidae family. In some patients, the parasite is responsible for severe complications such as cardiac manifestations, gastrointestinal involvement and neurologic disease. Imported Chagas disease by immigration in non-endemic countries poses the threat of the infection transmission by blood transfusion. In order to prevent this risk, the French Blood Services (EFS) introduced systematic screening of at-risk blood donors for anti-T. cruzi antibodies, in May 2007. The concerned donors are people originating from an endemic area, donors with mothers originating from such an area and individuals who had lived in or travelled to endemic areas. Donors were screened with two different Elisas simultaneously: one Elisa using purified parasite lysate antigens and the second one composed of recombinant antigens. Positive results and discrepant results were further assayed with an immunofluorescence assay. A seroprevalence assay was performed in the 17 French blood centres after an 18-month testing period from May 2007 to December 2008. During this period 4,637,479 million donations were collected. Out of these 163,740 donations were tested (3.5%). The prevalence of anti-T. cruzi antibodies was one in 32,800 donations. Five positive donors were identified. All of them were originating from endemic areas. A rate of 0.85% indeterminate results was found. Screening strategy revision was decided to reduce the number of donors unnecessarily deferred.