Anthrax is an ancient disease associated with the plagues in biblical Egypt and modern bioterrorism. Three clinical syndromes result from exposure to anthrax spores: cutaneous,inhalational, and gastrointestinal. Cutaneous anthrax is the most common naturally occurring syndrome; inhalational anthrax is most likely to result from airborne release of spores. Prophylactic and early treatment can improve the mortality from inhalational anthrax. A vaccine is available, but has many limitations. New vaccines are currently being developed.