As a rule, coagulase-negative staphylococcal infections in the neonate is an acquired iatrogenic infection. It usually occurs in premature infants with an in-dwelling catheter. Clinical and laboratory criteria are used to differentiate contaminated samplings from true infection. the frequency of methicillin-resistant strains justifies the use of vancomycin combined with an aminoglycoside and, in the first days, with rifampicin, all drugs administered in doses calculated for the post-conception age. This treatment is also administered in mother-to-foetus infections caused by CNS.