Amongst medications used in hospitals, antibiotics represent the most expensive therapeutic group; their use is constantly growing. Beyond acquisition costs, antibiotherapy costs must be approached at a broader level, including costs of preparation, administration, efficacy or inefficacy, monitoring, side effects treatment, and long-term costs resulting bacteria resistance. An attempt to cost containment in antibiotherapy can only result from a global, multidisciplinary strategy, with at all levels, as main objectives, the improvement of the quality and effectiveness of treatment adequate relevance of drug selection and therapy assessment.