Data in the literature as well as authors own observations concerning a possible relationship between the acute phase reaction and changes of the hemostatic variables, which may favour or trigger a thrombotic event, are reviewed. Acute phase reaction is usually accompanied by increased plasma levels of fibrinogen, von Willebrand factor and clotting factor VIII, while endothelial cells in culture added proinflammatory cytokines were found to express tissue factor activity, to release von Willebrand factor and to increase the production of plasminogen activator inhibitor. Evidence is also provided that inflammation would lead to an increase of plasma antithrombin III while the protein C system is down regulated. It is also considered that the above-mentioned changes of hemostatic variables would favour the local deposition of fibrin and platelets while attempting to prevent an intravascular dissemination of fibrin formation.