Endotoxic shock is a major health threat caused by Gram-negative bacteria and their unique cell wall component, lipopolysaccharide which induces exaggerated production of proinflammatory cytokines. Although macrophages play a central role in the pathogenesis of endotoxic shock, NK1+ cells are also involved in this mechanism. NK1+ cells comprise two major populations, namely NK cells and NKT cells. It remains, however, elusive whether either NK cells, NKT cells or both are involved in induction of endotoxic shock. This review will focus on the relative contribution of these NK1+ cells to the pathogenesis of endotoxic shock.