Thermal injury-associated endotoxemia affects the in vitro induction of interleukin -1b (IL-1b) synthesis by inflammatory stimuli. Pathophysiological effects related to the interaction between bacterial endotoxins and human monocytes/macrophages are complex and may have significant impact on defense response of burn host. Therapeutic approaches in critically ill burn patients should be considered in the context of the overall biological activity of endogenous mediators of immune and inflammatory reactions involved.