Terrorist acts and the fear of terrorism have become a part of everyday life in the early 21st century. Among the threats most feared is bioterrorism, including the intentional release of smallpox. With the invasion of Iraq and toppling of the Saddam Hussein regime, acute bioterrorism fears have abated; however, an ongoing threat remains. This article addresses the need for knowledge and rational policies in dealing with potential bioterrorism attacks. It presents information on four of the most likely bioterrorism agents: smallpox, anthrax, botulism, and plague. It illustrates the importance of accurate knowledge and rational decision making in addressing the threat of terrorism through the intentional release of biological weapons such as smallpox. Finally, it provides information essential for social workers to make informed practice decisions, to educate clients and the public, and to advocate for sound public policy.