The hepatoprotective activity of ethanolic extract of the whole plant of Cayratia trifolia (L.) Domin was evaluated against nitrobenzene (NB) (50 mg/Kg bw, orally) induced hepatic damage in rats. The extract at the dose of 200 mg/kg body weight were administered orally once every day for 7 successive days. The treatment restores the elevated levels of the liver marker enzymes such as alanine amino transferase, aspartate amino transferase, alkaline phosphatase in serum and lipid peroxidation in tissue homogenate. Whereas the antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase remains decreased in carcinogen induced group and after treatment the levels of antioxidant enzymes increased. Histopathological analysis of the NB induced animals showed severe necrosis and fatty infiltration in liver. After treatment with C. trifolia the rats showed regeneration of hepatocytes. The results thus support the use of C. trifolia as a hepatoprotective agent.Colegio de Farmacéuticos de la Provincia de Buenos Aires