Bone marrow transplantation (BMT) is a promising method of treatment for children with resistant malignancies. The discrepancies in the results of BMT from institution to institution are based on patient selection, timing of transplantation, and preparatory regimens that differ from place to place. Studies that address specific questions are needed: questions like Under what conditions is BMT superior to conventional chemotherapy? Which preparatory regimen is superior? What are the results based on the status of the patients' malignancies and quality of life? Multi-institutional studies are needed to answer these questions.