Despite limited resources, emergency medical settings will be called upon to play many roles in the context of disasters and terrorist attacks that are related to preparedness, surveillance, mental health services delivery, and staff care. Such settings are a central capture site for those individuals likely to be at highest risk for developing mental health and functional problems. Because much of the potential harm to survivors of disaster or terrorism (and their families) will be related to their mental health and role functioning, preparedness requires the active integration of behavioral health into emergency medicine in every component of disaster response. There are many challenges of doing this including: (1) finding ways to integrate activities of the medical care, emergency response, and public health systems; (2) determining whether an incident has actually occurred; (3) making differential diagnoses and managing other aspects of initial medical needs; and (4) coping with the risks associated with system overload and failure. Delivery of direct mental health care must include: (1) survivor and family education; (2) identification and referral of those requiring immediate care and followup; (3) group education and support services; and (4) individual counseling. In order for effective response to occur, the integration of psychosocial care into disaster response must occur prior to the disaster itself, and will depend on effective collaboration between medical and mental health care providers. At workplaces, emergency medical care centers must ensure that staff and their families are properly trained and supported with regard to their disaster functions and encouraged to develop personal/family disaster plans.