Viridans group streptococci (VGS) are a heterogeneous group of saprophytic facultative anaerobic bacteria that are part of the normal flora of the oral cavity. They are also major pathogens in different orofacial infections. The increased resistance to multiple antibiotics in this group of bacteria becomes important in nosocomial infections which occur as a result of prolonged antibiotic therapies inpatient where these common microorganisms are replaced by multi-resistant bacteria that contribute not only to the growing epidemic of bacterial resistance but also put in risk the health of patients.