In the development of sepsis DIC is a common complication. Several studies presented in this paper show a coincidence between the development of DIC and depletion of Antithrombin III, a serine protease inhibitor which inhibits a large scale of activated clotting factors. It seems very probable that substitution therapy should be of benefit in the treatment of sepsis-related DIC and may improve the outcome of septic patients. Physiological and clinical findings are put together to clarify the basic rationale for running clinical trials and future studies.