Enterococci are microorganisms with a remar- kable ability to adapt to their environment. Two species have a significant clinical implication, Enterococcus faecalis and Enterococcus faecium. The risk factors for colonization and infection must be recognized, including prior treatment with antibiotics such as cephalosporins or quinolones. Because of their native resistance to several classes of antibiotics and the increase of acquired resistance to penicillins, the initial empiric treatment of a severe infection in a patient at risk of enterococcal infection often includes a glycopeptide. A restriction in the empirical use of cephalosporins or quinolones and a targeted antibiotic therapy following receipt of the antibiogram are essential to prevent the emergence of enterococcal strains and especially vancomycin-resistant enterococci.