Coagulase-negative Staphylococci (CNS), considered for many years to be commensal bacteria of the skin are now recognized as major agents of nosocomial infection. Bacterial factors (increased resistance), host factors (immune status) and multiplication of the portals of entry (presence of foreign material) have contributed to the increased incidence of nosocomial infections. The importance of the role of NCS in urology is due to their great capacity to colonize catheters and most prostheses. The particular organization of these bacteria into a conglomerate called biofilm is responsible for prosthetic infections, which can impair renal function and can sometimes be life-threatening. The authors review the current increase of the number of CNS isolated in urology departments and describe the various therapeutic strategies that can be proposed to eradicate these bacteria.