Activation of the so-called contact system has 2 major consequences; initiation of the intrinsic pathway of coagulation and the release of bradykinin, a highly potent proinflammatory peptide inducing vascular permeability and capillary leakage. Several significant human pathogens have the ability to activate the contact system, and the potential significance of this mechanism in bacterial virulence, including its role in sepsis, is discussed in this review.