The present study was conducted to evaluate whether the aqueous extract of the herb, Phyllanthus niruri (PN) can effectively cure liver from nimesulide (NIM) induced oxidative stress in vivo. In our experiments, we have seen that administration of PN through intraperitoneal route is more effective in hepato-protection than oral administration. PN (100 mg/kg body weight) was, therefore, administered intraperitoneally for 5 days post to NIM application (10 mg/kg body weight/twice daily) for 7 days in mice. Levels of antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT), non-protein thiol reduced glutathione (GSH) and lipid peroxidation end-products were then determined. NIM administration caused significant depletion of the levels of SOD, CAT and GSH along with the increased levels of lipid peroxidation. Post-treatment with PN rapidly restored most of the NIM-induced oxidative changes compared to those obtained by the self recovery of liver. Histological studies supported these results. In addition, studies showed that PN could scavenge free radicals. Antioxidant property of PN has been compared with that of potent antioxidant, vitamin E. Besides, the effect of a non-relevant protein, BSA, has also been included in the study. Combining, data suggest that NIM induced oxidative stress in the liver and that could be cured by the beneficial effect of PN.