Foreign body implants are highly susceptible to microorganism infection. The infectious agents may be of low pathogenicity (such as S. epidermidis) or involve more virulent strains (such as S. aureus). The common denominator for the three main elements that play a role in the physiopathology of such infections (bacteria, neutrophils, and different biomaterials) are host proteins deposited over the surface of the devices immediately after their implantation. These proteins modulate that host cells response but can also promote Staphylococcus adhesion to the biomaterial. Neutrophils and other cells such as fibroblasts adhere to several extracellular matrix proteins such as fibronectin, fibrinogen, collagen, vitronectin, via specific cell surface receptor. The evolution of the technology and the increasing numbers of long-term artificial implants require a better understanding of fundamental mechanisms of foreign body infections to reduce their incidence and optimize their treatment.