Botulinum toxin is regarded as the most lethal substance known. It is estimated that the human LD50 for inhalation botulism is 1 to 3 nanograms of toxin/kilogram body mass. Although only three cases of inhalational botulism have been described, an understanding of the pathophysiology of food-borne outbreaks, wound botulism, and infant botulism, and their therapies, enables the medical community to plan treatment in the event of an aerosol release of botulinum toxin. Antitoxin, vaccine, and F(ab')2 immune fragment therapies are discussed as adjuncts to supportive therapy.