Myelodysplastic syndromes (MDS) are a group of disorders of the blood or bone marrow that frequently indicate an incomplete or early manifestation of acute leukemia. Peripheral blood cytopenias and abnormal hematopoiesis characterize the clinical picture. Approximately 25–50% of persons with MDS develop acute nonlymphocytic leukemia (ANLL), which is why the term “preleukemia” is often used to describe these hematologic disorders. The mean survival time is approximately 2 years. The pathophysiologic changes related to ineffective hematopoiesis may result in multiple clinical problems. Nursing care is focused on (a) identification of patient/family teaching needs; (b) assessment, prevention, and treatment of complications related to anemia, thrombocytopenia, and granulocytopenia; and (c) providing psychosocial support to the client/family throughout the course of the illness.