The threat of exposure to chemical warfare agents has traditionally been considered a military issue. Several recent events have demonstrated that civilians may also be exposed to these agents. The intentional or unintentional release of a chemical warfare agent in a civilian community has the potential to create thousands of casualties, thereby overwhelming local health and medical resources. The resources of US communities to respond to chemical incidents have been designed primarily for industrial agents, but must be expanded and developed regarding incident management, agent detection, protection of emergency personnel, and clinical care. We present an overview of the risk that chemical warfare agents presently pose to civilian populations and a discussion of the emergency medical and emergency public health issues related to preparedness and response.