Since the US terrorist attacks of September 11, 2001, concern regarding use of chemical, biological, or radiological weapons is heightened. Many victims of such an attack would present directly to health care facilities without first undergoing field decontamination. This article reviews basic tenets and recommendations for health care facility-based decontamination, including regulatory concerns, types of contaminants, comprehensive decontamination procedures (including crowd control, triage, removal of contaminated garments, cleaning of body contaminants, and management of contaminated materials and equipment), and a discussion of methods to achieve preparedness.