Background: Myelodysplastic syndromes (MDS) are malignant stem-cell diseases that are usually diagnosed in elderly patients who present with anemia or, less commonly, bi-or pancytopenia. Their incidence in persons over age 80 is above 50 new cases per 100 000 persons per year. Their clinical course is highly variable. About one-quarter of all patients with MDS develop acute leukemia. The median survival time from the moment of diagnosis is about 30 months. Methods: We selectively searched the PubMed database for pertinent articles and guidelines from the years 2000-2013. We used the search term "myelodysplastic syndromes." Results: MDS are diagnosed by cytology, with consideration of the degree of dysplasia and the percentage of blast cells in the blood and bone marrow, and on a cytogenetic basis, as recommended in the WHO classification. In particular, chromosomal analysis is necessary for prognostication. The Revised International Prognosis Scoring System (IPSS-R) enables more accurate prediction of the course of disease by dividing patients into a number of low-and high-risk groups. The median survival time ranges from a few months to many years. The approved treatments, aside from transfusion therapy, include iron depletion therapy for low-risk patients, lenalidomide for low-risk patients with a deletion on the long arm of chromosome 5, and 5-azacytidine for high-risk patients. High-risk patients up to age 70 who have no major accompanying illnesses should be offered allogenic stem-cell transplantation with curative intent. The cure rates range from 30% to 50%. Mucositis, hemorrhages, infections, and graft-versus-host diseases are the most common complications of this form of treatment. Conclusion: Myelodysplastic syndromes are treated on an individualized, risk-adapted basis after precise diagnostic evaluation and after assessment of the prognosis. More studies are needed so that stage-adapted treatment can be improved still further.