This study was undertaken to evaluate the antioxidant potential of A. lanata on oxalate mediatedfree radical toxicity in ethylene glycol induced calcium oxalate urolithic rats. Calcium oxalate(CaOX) stone was induced by 0.75% ethylene glycol in drinking water for 28 days. From 29th dayonwards, the CaOX urolithic rats were treated with A. lanata aqueous suspension (2,000 mg/kgbody weight/dose/day) orally for another 28 days. At the end of experimental periods theanimals were sacrificed, samples were collected and analyzed the lipid peroxidation product,protein oxidation product, enzymatic and non-enzymatic antioxidants in normal andexperimental groups. Lipid peroxidation and protein oxidation products were significantlyelevated while enzymatic and non-enzymatic antioxidant levels were significantly decreased inethylene glycol induced CaOX urolithic rats when compared with control rats. The abovealterations were reverted to near control in rats treated with aqueous suspension of A. lanata. Thisstudy suggests that A. lanata could prevent the free radical formation from calcium oxalateurolithiasis in rats and protecting the renal cells from oxidative injury.