This multiservice publication serves as a guide and a reference for trained members of the Armed Forces Medical Services and other medically qualified personnel on the recognition and treatment of biological warfare (BW) agent casualties. Its purpose is to provide an overview of potential BW agents directed against human beings, the problems that might be created during an attack in which a BW agent is utilized, and the current methods available to medical personnel for recognizing, preventing, and managing these problems. Information contained in this publication may also be relevant for the diagnosis and treatment of patients with naturally acquired diseases or illnesses due to pathogens with BW potential. BIOLOGICAL WARFARE AGENTS. Chapter 1 provides information on the threat of BW agents against the U.S. Armed Forces and civilian population. It also discusses its employment; novel threat agents policies and guidelines; classification of BW agents; and enemy's most effective modes of delivery (aerosol, foodborne, waterborne, vectorborne, or injection). It discusses how BW agents enter the body via the portals of entry and how its effects are preventable through a number of protective measures. RECOGNITION. Chapter 2 discusses epidemiology; warning and detection; surveillance; sample collection; medical reporting; and also discusses the U.S. Public Health Biological Warfare Monitoring and Assessment. BACTERIAL AGENTS. Chapter 3 describes bacterial agents including cells and spores which comprise the greatest number of pathogens in the list of potential BW agents. This list includes anthrax, brucellosis, melioidosis and glanders, plague, Q fever, tularemia, and cholera. Discussion of each agent includes etiology; reservoir; mode of transmission; endemic disease; delivery method; environmental detection; prevention; clinical presentation; diagnosis; treatment; control of patients, contacts, and treatment areas; and medical evacuation. VIRAL AGENTS. Chapter 4 discusses potential viral BW agents which include smallpox; Venezuelan equine encephalitis; Western equine encephalitis (WEE); Eastern equine encephalitis (EEE); and viral hemorrhagic fevers (VHFs). Discussion of each agent includes etiology; reservoir; mode of transmission; endemic disease; delivery method; environmental detection; prevention; clinical presentation; diagnosis; treatment; control of patients, contacts, and treatment areas; and medical evacuation. TOXINS. Chapter 5 describes toxins which include Clostridium (C.) botulinum; C. perfringens; ricin; saxitoxin; staphylococcal enterotoxin B (SEB); and trichothecene mycotoxins. Discussion of each agent includes etiology; reservoir; mode of transmission; endemic disease; delivery method; environmental detection; prevention; clinical presentation; diagnosis; treatment; control of patients, contacts, and treatment areas; and medical evacuation. IDENTIFICATION TECHNOLOGIES. Chapter 6 provides information on different methods for identifying BW agents. It discusses the advantages and disadvantages of using orthogonal testing; lateral flow immunoassays; enzyme-linked immunosorbent assays; electrochemiluminescence (ECL); and polymerase chain reaction. This chapter also discusses the confidence levels of laboratory analysis.