Biological weapons (BW) are devices intended to deliberately disseminate disease–producing organisms or toxins in food, water by insect vector, or as an aerosol. Biological agents may be used as weapons that could cause disease and death in large number of people to cripple a city or a region. Anthrax is one of the most serious biological agents. Other biological weapons that cause high morbidity and mortality might cause public panic and require special action for public health preparedness. These agents include plague, small pox, botulism, tularemia and viral hemorrhagic fever. Plan must be followed to accomplish the society preparedness to the biological attack that include: Hospital preparation and training the personnel of public health systems to deal with such attack, early detection of unusual disease and supply diagnostic reagents to state and local public health agencies.