Chemical warfare is not a popular topic, and most military health care providers do not willingly become familiar with it. This was painfully obvious during Operation Desert Shield/Desert Storm when it soon became apparent that many health care providers knew little about the effects of chemical agents or about the medical defense against them. This ignorance was particularly striking in view of the seven-decade-long history of modern chemical warfare and the well-publicized use of mustard and nerve agent during the Iran-Iraq war in the 1980s. The prevailing attitude of military health care providers was that chemical agents would be used only on Hmong, Mghans, Kurds, or similarly unprepared and unprotected groups of people. Further, many health care providers believed if chemical weapons were used the outcome would be disastrous, defense would be impossible, and the casualty rate and loss of life would be high. Through education, however, medical professionals involved in Operation Desert Shield/Desert Storm learned that medical defenses were possible and effective, that chemical casualties could be saved and returned to duty, and that mortality could be minimized. Further, they realized that they might be the target of chemical agents. More importantly, they rapidly learned that General Pershing's warning (written shortly after World War I) about chemical agents was still true: ' ... the effect is so deadly to the unprepared that we can never afford to neglect the question.' The purpose of this handbook is to provide a small and concise handbook for attendees at the Medical Management of chemical Casualties Course. The handbook is small so that it can be easily carried, and the format is such that it can be easily updated. It is not intended to be a definitive text on the management of chemical casualties.