We studied the effect of oral supplementation with L-ascorbic acid (50 mg/100 g body weight) on nickel sulfate (2.0 mg/100 g body weight, i.p.) induced lipid peroxidation in the testes of Wister strain male albino rats. Testicular lipid peroxide and glutathione (GSH) levels and the activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were estimated. Nickel sulfate treatment significantly increased the level of testicular lipid peroxide and decreased all antioxidant enzymes activities and GSH concentration. Simultaneously treatment of L-ascorbic acid exhibited a possible protective role on the toxic effect of nickel sulfate on testicular lipid peroxide and GSH concentration as well as antioxidant enzymatic defense system.