Allogeneic bone marrow transplantation (BMT) is a useful approach for treating patients with chronic myelogenous leukemia (CML). In patients who lack a suitable donor, various approaches to utilize the patient's own hematopoietic stem cells obtained from bone marrow and/or peripheral blood have been developed. Preferential recovery of normal human hematopoietic progenitors over CML clone in long-term bone marrow culture (LTBMC) has been observed for a long time. LTBMC initiated in tissue culture (TC) flasks to that in "Lifecell" bags, which are gas-permeable plastic bags in which feeder-layer cells cannot adhere, has been investigated for several years. In our laboratory, cells were incubated in the presence of various growth factors to develop improved methods for stem cell expansion. Sustained hematopoietic stem cell growth in the absence of a feeder layer in plastic gas-permeable bags has been observed. Growth of marrow from patients with CML is being investigated extensively. Combining effective drugs to decrease the Philadelphia (Ph) clone prior to bone marrow harvest and the use of cultured bone marrow may provide a useful method for treating patients with CML. Results of various international studies are also discussed below.