Every year, major chest injury is involved in 56% of deaths in trauma victims. Blunt chest trauma apparently plays a crucial role in trauma-induced death of multiply injured patients. Therefore, the aim of this study was to evaluate the impact of different types of injuries, including lung tissue damage, on the release of various prostanoids. In a prospective study, the release of arachidonic acid (AA) metabolites was estimated in patients suffering blunt chest trauma alone, i.e., single thoracic injury, and in multiple injured patients including blunt chest trauma. The results were compared with those of patients suffering from single long bone fractures of the leg without additional injury. The plasma concentrations of the AA metabolites, prostacyclin, thromboxane, prostaglandin F2 alpha, and prostaglandin M were determined immediately after admission and in hourly and daily intervals thereafter. Despite clearly different injury scores, elevated levels of circulating AA metabolites were found in the plasma in all patients. This study reveals that any trauma increases significantly the release of prostanoids into the peripheral blood without regard to the impact of tissue damage. This phenomenon is, however, most pronounced following lung injury. On the basis of these results we suggest that there is a specific impact of those mediators in blunt chest trauma. The prostanoids apparently are suitable to describe and even to monitor the extent of thoracic trauma, thus giving additional information in some respect to the individual outcome.