The myelodysplastic syndrome (MDS) is a clonal stem cell disorder characterized by ineffective blood cell production and dysplasia. The most important clinical findings are anemia, leucopenia and trombocytopenia or their combinations. The MDS patients could have chronic asymptomatic cytopenias or symptomatic anemia, infections and bleeding disorders and there is a variable risk of transformation to acute leukemia. It is generally an elderly disease and though, its' etiology is unknown most of the time; chemotherapy and radiotherapy may exert a mutant effect on the stem cells. The incidence of MDS with unknown etiology is 4/100000 and this ratio exceeds that of acute myeloid leukemia.