Book excerpt: Selective decontamination is a technique which combines short-term and long-term antimicrobials to prevent or treat the acquisition and subsequent carriage of microorganisms causing late colonization and infections. The antimicrobials are selective in that they leave the indigenous, mostly anaerobic flora more or less intact, whilst the effective decontamination provides a genuine breakthrough in the endogenous route of pathogenesis. The improvements in decontamination techniques presented here offer significant reduction in infection related morbidity and mortality among trauma patients.