Myelodysplastic syndromes (MDS) belong to the most frequently seen malignant diseases of the bone marrow, especially in the elderly. Howver, diagnosis and prognosis are often difficult to establish, and treatment decision-making is hampered not only by the lack of available therapies but also by the lack of understanding of pathophysiology. This book, authored by members of the MDS working groups of the Department of Hematology, Oncology and Clinical Immunology of the Heinrich-Heine University of Düsseldorf (Germany) and the Georg-August University Göttingen (Germany), provides an overview and discussion of the pathophysiological concepts, diagnostic procedures and therapeutic approaches in MDS.