Inflammation is involved in various diseases, including chronic inflammatory disease and arthritis. The inflammation induced by the production of cyclooxygenease (COX)-2 and inducible nitric oxide synthase (iNOS), which are important mediators of inflammation. In this study, we investigated the ethanol extract of Tribulus terrestris (ETT) inhibited expression of COX-2 and iNOS in lipopolysaccharide(LPS)- stimulated RAW264.7 cells. We observed that ETT significantly decreased release of NO production in a dose-dependent manner in LPS-stimulated RAW264.7 cells. ETT also suppressed expression of proinflammtory cytokines, such as TNF-α and IL-4 in macrophage cell line. Our findings suggest that ETT inhibits expression of mediators related to inflammation and expression of inflammatory cytokines, which has a beneficial effect on various inflammatory diseases.