Macrophages are innate immune cells that play a major role in activation of inflammatory processes to eliminate microorganisms, toxins and invading substances, by generating free radicals; nitric oxide (NO), reactive oxygen species (ROS) and proinflammatory mediators. Vernonia cinerea L. is one of the herbal plants that has been used in local remedies for various inflammatory diseases. The aim of this study was to investigate the antioxidant activities of Vernonia cinerea extract in macrophages stimulated with endotoxin and cytokines. Macrophage cell lines (RAW264.7) treated with lipopolysaccharides (LPS) and interferon-g (IFN-g) increased NO/ROS productions as well as enhanced protein synthesis of inducible nitric oxide synthase (iNOS) enzymes. The results showed that Vernonia cinerea water extract (VE) could decrease NO/ROS in a dose dependent manner, and significantly diminished iNOS enzyme expressions in the LPS/IFN-g stimulated cells. Moreover, VE at the tasted concentrations (62.5 – 500 mg/mL) had no effect on cell viability in the macrophages. Basically, this study demonstrates that VE has antioxidant property via inhibition of NO productions and reduction of iNOS enzyme synthesis.