The impact of the next pandemic influenza is likely to be far greater, by orders of magnitude, than most bioterrorism (BT) scenarios. A written pandemic emergency plan and establishment of emergency management teams are critical to mounting a coordinated and effective response to what will be a catastrophic event. Members of these teams should include public health, medical, emergency response and public safety officials, organized at each local, state and federal level. The tragic events of September 11, 2001 and the subsequent anthrax attacks have substantially increased funding and support for bioterrorism planning in the United States. Thus, public health officials have an unprecedented opportunity to strengthen current systems' planning efforts by promoting dual use bioterrorism/pandemic influenza plans. Combining lessons learned from the 2001 terrorist incidents, recent preevent smallpox vaccine programs and the history of past influenza pandemics, more effective strategies can be developed. For example, enhanced influenza surveillance systems can provide data that will not only provide early identification of a novel influenza strain, but will provide more timely recognition of other outbreaks of infectious diseases, including public health threats that may initially present as an influenza-like illness (ILI). In recent years, we have witnessed emerging and reemerging infectious disease threats that have presented us with challenges similar to those posed by an influenza pandemic. Such events highlight the need for advance planning to ensure an optimal response to a health emergency that is certain to be unpredictable, complex, rapidly evolving and accompanied by considerable public alarm. While advance warning for a terrorist attack is unlikely, the warning already exists for a possible new influenza strain, as evidenced by the recent cases of H5N1 in Hong Kong and the rapid global spread of cases of Severe Acute Respiratory Syndrome.