In contrast to the situation, when injury to gastrointestinal or nervous system dominates, hematologic syndrome of acute radiation syndrome is the only organ injury syndrome which an irradiated person can survive. Up to 3.5 Gy dose, a victim may survive without significant medical assistance, while with such assistance it is possible to survive up to approx. 5–6 Gy irradiation without bone marrow transplantation. Above 6 Gy and up to approx. 10–12 Gy, survival is possible only with bone marrow transplantation from unirradiated person. With irradiation doses exceeding the latter values, injuries to other organ systems dominate. Actual possibility of providing medical care would strictly depend on the number of victims. With decreasing number of irradiated persons the possibility of providing full and advanced care would increase, while increasing number will gradually reduce such a possibility, all the more because in such case rescue services including health care providers would be affected as well. With a greater number of the irradiated, survival of those who could be saved would depend on organizational skills in triage, evacuation and only finally on the quality of medical assistance.