Refractory anemia, also known as myelodysplastic syndromes, forms a group of clonal diseases characterized by cytopenias with mostly rich bone marrow. Preferentially reaching an older population, the prognosis depends on both comorbidities and characteristics of the disease, which have been grouped into a score established in 1997 ("IPSS = International Prognostic Scoring System") and revised in 2012 ("R-IPSS = Revised IPSS"). Overall survival and risk of transformation into acute nonlymphoblastic leukemia can now be estimated fairly accurately. Based on these characteristics, the treatment will be mainly supportive or will use several new molecules: growth factors, lenalidomide, 5-azacitidine, etc. A minority of patients may also benefit from allogeneic BMT or sometimes immunosuppressive therapy.