The importance of Withania somnifera root extract in the regulation of lead toxicity with special reference to lipid peroxidative process has been investigated in liver and kidney tissues. While lead treatment (0.5 mg kg(-1)body wt. day(-1)for 20 days) enhanced hepatic and renal lipid peroxidation (LPO), administration of plant extract in the doses of 0.7 g kg(-1)and 1.4 g kg(-1)body wt. day(-1)along with equivalent doses of lead acetate for 20 days significantly decreased LPO and increased the activities of antioxidant enzymes, viz., superoxide dismutase (SOD) and catalase (CAT), thus retaining normal peroxidative status of the tissues. We suggest that the ameliorating role of root extract of W. somnifera in the lead intoxicated mice could be the result of its antiperoxidative action.