The bone marrow failure syndromes include a group of disorders than can be either inherited or acquired. These diseases are disorders of the hematopoietic stem cell that can involve either one cell line or all of the cell lines (erythroid for red cells, myeloid for white blood cells, megakaryocytic for platelets). The lymphocytes, which are involved in lymphoproliferative disorders, are usually spared. The inherited bone marrow failure syndromes include Fanconi anemia, dyskeratosis congenital, Diamond-Blackfan anemia, and other genetic disorders. The most common cause of acquired bone marrow failure is aplastic anemia. Expert authors present current diagnosis, treatment, and management strategies for these syndromes. The articles in this issue are divided into 3 classifications: global marrow failure, lineage-restricted marrow failure, and marrow failure and evolution of neoplastic clones.