The authors reviewed the data on case management of Hadassah University Hospitals in Jerusalem, Israel, for the first 2 years of the last wave of Palestinian terrorist attacks, beginning September 29, 2000. Hadassah's 2 medical centers in Jerusalem have treated approximately 40 percent of the approximately 5,000 Israeli casualties of terrorist attacks during the study period, many of whom were involved in mass casualties incidences (MCI's). Terrorism injuries were related to one or more of the following terrorist tactics: stoning, stabbing, lynching, shooting, hand-grenade, Molotov cocktail, suicide bombing, and bombing. Data indicate that terrorism attacks inflicted serious injuries that placed increased demands on hospital resources compared with other forms of trauma. The authors argue that terrorism forms a new class of epidemiology that may affect the civilized world for years to come, such that its special characteristics should be familiar to the medical community and public-policy decisionmakers. One of the tasks that each medical manager should acquire is the ability to manage MCI, defined as an incident in which the medical system is overwhelmed and the balance between resources and demands is undermined. The primary aim of the management of the event is to decrease mortality, morbidity, and permanent disability in the victimized population. The main issue in MCI management is administrative, involving triage (prioritization of treatment of salvageable victims), transportation of mass numbers of victims, and optimization of the use of resources. In order to prepare for the medical management of terrorism's victims, the most likely types of threats and consequent injuries should be identified and treatment and logistical models developed. Standard operating procedures for each type of terrorist attack should be put in writing. The procedure manuals should include generic procedures for managing all types of threats, followed by those that are specific to each type of attack. Particular departments and units should have their own chapters in the manual. Plans should include optimal assignment of personnel and optional locations for additional admission areas. Early preparations should include the purchasing of protection gear, decontamination facilities, backup communication systems, antidotes, etc. The final stage of preparations is the holding of drills, specifically a "round table" drill for managers and a full-scale drill with full participation of the entire staff. Each drill should be followed immediately with a debriefing process. 14 notes