The military is subject to traumatic wounds of various types and severity. Such wounds are predisposed to infection because they 1) tend to be extensive and deep, 2) may affect areas of normal carriage of potentially pathogenic bacteria in the gastrointestinal tract, upper respiratory tract, and the female genital tract, 3) typically produce tissue damage, 4) may introduce foreign bodies, 5) may interfere with local blood supply, 6) tend to produce ischemia, edema and hemorrhage, 7) may be complicated by fractures or burns and 8) may lead to shock and overwhelming of the body's systemic defenses. It will not always be possible in the military setting to cleanse and debride the wound promptly and effectively or to promptly provide surgery in the event of damage to vital structures. In the active military setting, the probability of wound infection following trauma is relatively high. In the absence of rapid identification of infecting flora and provision of information on antimicrobial susceptibility, clinicians must resort to empiric therapy rather than a tailored therapy. There is a tendency to use one of the top available agents that would likely be active against the vast majority of bacteria. This leads to increases in antimicrobial resistance, an important problem.