The protective effect of a methanolic extract (ME) of Acorus calamus against alcohol-induced hepatotoxicity and oxidative stress was studied in rats. The in vitro assays using DPPH and ABTS showed a strong antioxidant activity of the extract with the total polyphenolic content of 156 mg/g. Chronic ethanol administration causes an increase in oxidative stress and tissue injury with decreased antioxidant status. In this study, continuous administration of ethanol (7.9 g/kg body weight/day) for a period of 6 weeks resulted in a significant (p < .001) increase in the levels of serum aspartate aminotransferase, serum alanine aminotransferase, alkaline phospahatase, and bilirubin with the decreased level of total antioxidant status. Moreover, the levels of lipid peroxidation markers (malondialdehyde and hydroperoxides) as well as protein carbonyl content were also increased (p < .001), whereas the levels of non-enzymic antioxidants (glutathione, vitamin C, and vitamin E) decreased significantly in the liver tissues of ethanol-administered control rats. Pretreatment of rats with ME at doses of 300 and 600 g/kg body weight before alcohol administration significantly reduced the hepatic marker enzymes, level of lipid peroxidation, and protein oxidation, and increased the enzymatic and non-enzymatic antioxidant levels in liver. These observations were supplemented by histopathological examination of liver sections. Overall, the present study shows that the administration of ME ameliorates the antioxidant status as well as protects against the toxic effects of ethanol in rats, thereby suggesting its use as an effective botanical supplement for hepatoprotection.