The coagulase-negative staphylococci and in paticular Staphylococcus aureus are the most frequently isolated bacteria from IVDs, and are also major nosocomial pathogens. These microorganisms are prevalent bacteria from cutaneous and mucous membrane microflora of patients and lead to significant problems when an IVD is inserted. Since the insertion of an IVD provides a portal of entry by these bacteria which can cross from an unsterile external environment to the normally sterile blood and cause IVD-related infections. These bacteria also develop biofilms after they attach to the surface of IVD and complicate IVD-related infections by adding pressure on the dignosis and treatment. Recent molecular-based studies on biofilm found that the accessory gene regulator (agr) quorum-sesing system has a central role in the pathogenicity of staphylococci, paticularly that of S. aureus, and controlling these quorum-sesing systems also bring a bright future for preventing biofilm-associated infections. Finally, prevention strategies to control IVD-related infections are also focusing on antiobiotic prophylaxis and novel biomaterials of IVDs.