Aim: Nuclear factor E2-related factor-2 (Nrf2) regulates many cytoprotective antioxidants, and detoxifying enzymes, has been a hopeful approach for chemoprevention of cancer. We researched the chemopreventive impact of watercress on the DMBA-induced oxidative damage in the rat liver via the Nrf2/ARE signalling pathway in the present study. Material and Method: Female Wistar albino rats have categorized into three groups. The control was the first group, rats in the second and third groups were administered 7,12-dimethylbenz[a]anthracene (DMBA) (20 mg/kg b.w., i.p.) and rats in the third group were given daily doses of watercress (250 mg/kg b.w. Nasturtium officinale R.Br. for 4 weeks by oral gavage). Antioxidant and phase II detoxification enzyme activities, Nrf2 transcription factor level in liver, and serum ALT were determined. Also, histopathological analysis of the liver was performed. Results: We observed that watercress induces DNA-binding of Nrf2. It was related to increased enzyme activities of phase II detoxifying and the antioxidant. Our results also demonstrated that watercress ameliorated liver injury. Conclusion: Our data ensured considerable evidence that the dietary watercress ameliorates DMBA induced liver toxicity via regulating the activation of the Nrf2/ARE pathway which increases the expression of cytoprotective enzymes.