Lipid Peroxidation is an Indicator of Oxidative Damage in the Liver. Upon exposure to the free radicals, the ratio of natural antioxidants in the liver and reactive oxygen species gets altered which results in the production of various lipid peroxyl radicals and hydro peroxides. The extent of lipid peroxidation can be estimated by elevated levels of Malondialdehyde (MDA)  in Liver tissue. The present study was designed to screen the anti-lipid peroxidation activity of Acorus calamus rhizome extract in paracetamol induced hepatotoxic rat model. Paracetamol at the dose rate of 200 g/kg B.wt was given orally to induce hepatotoxicity and observed the rise in MDA levels. Forty eight hours after paracetamol administration the rats were treated with alcoholic and aqueous extracts of Acorus calamus rhizome for a period of ten days and the liver homogenate levels of MDA was estimated. The treatment of Acorus calamus rhizome extract in paracetamol induced hepatotoxic rats normalized the altered MDA levels in liver homogenate which are comparable with Silymarin, a standard hepato-protective drug.