Evaluation and management of victims of exposure to myelosuppressive radiation in a military, terrorist, or accidental event is challenging. The hematopoietic syndrome with marrow suppression and pancytopenia follows intermediate intensity radiation exposure and as such produces a clinical syndrome similar to that after myelosuppressive chemotherapy or stem cell transplantation. Therefore, hematologists, oncologists, and transplantation physicians have the opportunity and challenge to plan for care of irradiation victims. Management of the hematopoietic syndrome, as a component of acute radiation sickness, requires understanding its manifestations and implementation of clinical biodosimetry to provide appropriate therapeutic support. Hematopoietic growth factors may be of value if administered early as a component of supportive care. Planning for urgent stem cell transplantation for those with intermediate- to high-dose radiation (4-10 Gy) may be required. Establishing contingency plans for triage, assessment, supportive care, and treatment resembles the development of phase II trials, with defined eligibilities, treatment plans, and incorporated data collection to assess results and plan further improvements in care. The hematology/oncology community is most suited to participate in such contingency planning, and the necessary elements for its success are reviewed.