Lead (Pb) is a potential heavy metal of Group IV B of the periodic table which is soft, malleable metal having bluish white colour. Besides having its useful properties, it causes the reproductive abnormality in male Swiss mice. Testis is the important organ of reproductive failure caused by the accumulation of lead that develops reactive oxygen species that results oxidative stress in the tissues of organism. In the present study, 0.2% of lead acetate in drinking water was given to the mother from the first day of pregnancy and was continued up to lactation phase. At the end of lactation phase, the male pups were separated and after attaining sexual maturity at 9-10 weeks of age, the male pups were sacrificed and the testes were processed for the estimation of various biochemical parameters. Exposed animals showed significantly decrease in the level of antioxidant enzymes like catalase and peroxidase, decreased sperm count and markedly increased rates of sperm abnormality. Oxidative stress was measured in terms of malonicdialdehyde content of lipids. However, antioxidant vitamins like vitamin C, vitamin E and its combined action i.e. Vitamin (E+C) to the lead-induced mice groups could ameliorate the oxidative stress by declining lipid per-oxidation, increasing the level of catalase and peroxidase, increase in sperm count and reduce sperm abnormality.