Australian hospitals need to be prepared to deal with mass casualties from terrorist strikes, including bomb blasts and chemical, biological and radiation injury. Injuries from bomb explosions are more severe than those commonly seen in Australian hospitals. In disasters involving mass casualties in urban areas, many of the injured make their own way to hospital, often arriving before the more seriously injured casualties. Major hospitals in Australia should plan for large numbers of undifferentiated and potentially contaminated casualties arriving with minimal warning. It is critical that experienced and trained senior medical officers perform the triage of casualties in emergency departments, with frequent reassessment to detect missed injuries (especially pulmonary blast injury). Hospitals require well developed standard operating procedures for mass casualty events, reinforced by regular drills. Preparing for a major event includes training staff in major incident management, setting up an operational/control unit, nominating key personnel, ensuring there is an efficient intra-hospital communication system, and enhancing links with other emergency services and hospitals.