Biological weapons are considered weapons of mass destruction and mass casualty. Although the list of agents is numerous, those agents that could cause mass casualties by the aerosol route of exposure, considered the most deadly, are considerably smaller. Infectious biological agents include anthrax and the plague. Toxins include botulinum toxin and ricin toxin. Both lethal and incapacitating agents could have an adverse impact on the civilian healthcare delivery system in a biological terrorism scenario. Biological weapons are not new, but the technologies of production and delivery have been developed and perfected by nations during the twentieth century. Biological agents may be used because of several characteristics valued by the perpetrator. Aerosols are invisible, silent, odorless, tasteless, and are relatively easily dispersed without detection. They are relatively inexpensive to produce. These agents can be obtained for multiple culture collections, universities, commercial chemical and biological supply houses, foreign laboratories, and from field samples or clinical specimens. The primary means of protection are engineering controls, proper good laboratory and microbiological techniques, and common sense. Use of certain personal protective equipment and measures and decontamination procedures are equally important. There are two approaches to decontamination --surface and area or space. For surface decontamination, the effectiveness of a contaminant depends upon decontamination concentration, the concentration of the agent, type of agent, time of contact, and the environmental conditions. Area or space decontamination involves decontamination of equipment or materials within enclosed spaces. The Centers for Disease Control and Prevention (CDC) developed a strategic plan to address the deliberate dissemination of biological or chemical agents to reduce the vulnerability of the United States to terrorism. The plan includes preparedness planning, detection and surveillance, laboratory analysis, emergency response, and communication systems. 90 references