Foreign body infections share several properties: a high susceptibility to microorganisms which are usually of low pathogenicity (such as S. epidermidis) and with only some exceptions failure to respond to antimicrobial therapy without surgery. The common denominator for the three elements that play a role in the physiopathology of such infections (bacteria, neutrophils and different materials) is host protein deposited over the surface of the foreign body. Staphylococci and neutrophils selectively adhere to fibronectin and to a variable degree to laminin and fibrinogen. These proteins potentially modulate phagocyte function. With the progress of biotechnology and the increasing numbers of implantable prostheses, it will become critical to increase our understanding on how to prevent and treat foreign body infections.