In the event of a bioterrorist attack, rapid screening, agent identification, and confirmatory diagnosis will be critical, so that prevention and treatment measures can be implemented quickly. However, because few biologic agents thought likely to be used as biological weapons represent major public health problems in the United States, we have limited capacity to diagnose them, either at the state and local or the federal level. to begin to address this new public health challenge the Laboratory Response Network for Bioterrorism (LRN) was established.The LRN is a multi-level system designed to link state and local public health laboratories, clinical, military, veterinary, agricultural, water and food-testing laboratories. Operational in August of 1999, the LRN was established as a consequence of Presidential Decision Directive 39, increased congressional awareness of the huge biological weapons program in the former Soviet Union, the high level of risk to national security and subsequent emergency funding to the Centers for Disease Control and Prevention under the DHHS Operating Plan for Anti- Bioterrorism Initiative.