Fanconi's anemia is a rare autosomal recessive disease characterized by congenital abnormalities, a progressive pancytopenia and a predisposition to cancer. The diagnosis is based on an abnormal increase of spontaneous chromosome breakage, more specifically on a clear-cut increase of chromosome breakage in the presence of bifunctional alkylating agents. Eight complementation groups (A to H) have been defined, and the genes corresponding to four of these groups have been cloned (FANCA, FANCC, FANCF and FANCG). The function of the proteins encoded by the genes of Fanconi's anemia remains unknown. Numerous studies indicate that different cellular processes are probably involved, including DNA repair pathways, apoptosis, cell cycle regulation and oxygen metabolism. Nevertheless, the exact cellular and molecular mechanisms implicated in Fanconi's anemia remain a challenge for fundamental research. The treatment of Fanconi's anemia is also the subject of intense research, bearing principally upon bone marrow transplantation, which is successful in the case of HLA-identical sibling donors, and gene therapy, which is still at a preliminary stage on the clinical level.