Background: All physicians would need to address the psychosocial consequences of a mass casualty terrorist attack should it occur.Method: A review of evidence and expert opinion regarding psychosocial response to mass casualty incidents was performed. Data were obtained via the PubMed database in an English-language search using the terms PTSD secondary prevention, psychological first aid, and disaster psychiatry and the dates 1995 through 2004.Results: There is a National Institute of Mental Health consensus statement on the psychiatric response to mass violence, but sparse psychopharmacologic literature. Psychotherapeutic interventions are well studied in posttraumatic settings.Conclusions: The physician's response to mass casualty terrorism must address the high volume of patients with anxiety reactions and somatic symptoms likely to present for care. Supportive interventions include fostering a sense of safety and efficacy, connecting patients with communities and services, and helping parents talk about the trauma with their children. In the future, early pharmacologic interventions may be proven effective.