In patients with blood cancers such as myeloma, leukemia, or lymphoma, the chemotherapy and radiation that kill malignant cells also kill healthy marrow and its resident blood stem cells. Whether the cancer begins in the marrow itself or in lymphoid or other organs, anticancer treatment can deplete much of the body's reserve of blood-forming stem cells. Even patients with noncancerous blood diseases can develop a shortage of blood stem cells, as occurs in life-threatening anemias or immune disorders. In all these cases, a blood stem cell transplant can restore normal hematopoiesis.

Hematopoietic or blood stem cell transplants are also called bone marrow transplants or peripheral blood stem cell transplants, depending upon the location of stem cell collection.