Terrorist attacks by definition are designed to cause fear and panic. There is no question that a terrorist attack using biological agents would present a grave threat to stability of the society in which they were released. Early recognition of such a bioterrorist attack is crucial to containing the damage they could cause. As many of the most likely bioterrorism agents present with pulmonary disease, respiratory physicians may be crucial in the initial recognition and diagnosis phase, and certainly would be drawn into treatment of affected individuals. This review focuses on the biological agents thought most likely to be used by terrorists that have predominantly respiratory presentations. The primary focus of this review is on anthrax, plague, tularaemia, ricin, and Staphylococcal enterotoxin B. The pathogenesis, clinical manifestations and treatment of these agents will be discussed as well as historical examples of their use. Other potential bioterrorism agents with respiratory manifestations will also be discussed briefly.