To reduce the very high mortality rate due to septic shock, a new clinical entity has been defined: sepsis syndrome. The aggressive treatment of any sepsis syndrome should prevent the evolution towards a state of shock and thus reduce the risk of a fatal outcome. It consists in broad spectrum antibiotic therapy associated with hemodynamic support (volume resuscitation, vasopressors and inotropic agents) at the first signs of cardiocirculatory failure. Several pharmacological or immunological interventions--antagonists directed at mediators and multiple cytokines involved in the pathogenesis and perpetuation of sepsis syndrome and septic shock--have been successful experimentally. However, new therapies, such as those using monoclonal antibodies against endotoxins of TNF, cannot yet be considered established.