In this study, the effects of flunixin meglumin on the antioxidant status during endotoxemia were investigated. Thirty Balb/C mice were divided into three equal groups. Mice with no treatment formed the control group (group I). Mice treated with lipopolysaccharide (LPS) and LPS + flunixin meglumin (FM) formed groups II and III, respectively. All mice were sacrificed and tissue samples were collected 6 hours after treatments. Activities of Superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), as well as levels of malondialdehyde (MDA) and glutathione (GSH) were determined spectrophotometricalfy. LPS caused a significant (p<0.05) increase in levels of MDA (heart, kidney, spleen) which is an accepted biomarker of oxidative stress, and changed the levels of SOD, GPX, CAT and GSH. When FM was administered simultaneously with LPS, FM inhibited (p<0.05) the increase of MDA levels in all tissues. As results, LPS caused MDA levels and oxidative stress to increase. However, FM depressed the LPS induced increase of MDA levels. This antioxidant effect of FM may be beneficial in endotoxemia.