Aim: The present work was aimed at evaluating the effect of ascorbic acid on mercuric chloride induced changes on the cerebrum of Wistar rats. Methods: Thirty Wistar rats of average weight of 200g were divided into 6 groups of 5 rats each. In addition to normal diet, the animals in Group 1 were given distilled water, Groups 2 and 3 were administered 52mg/kg and 26.25mg/kg of mercuric chloride (HgCl) respectively while Groups 4 and 5 were administered 52mg/kg of HgCl and 5mg/kg of ascorbic acid and 26.25gm/kg of HgCl and 5mg/kg of ascorbic acid respectively. Group 6 was administered 5mg/kg of ascorbic acid through oral route, daily for 3 weeks. Results: Oxidative stress assay showed a significant decrease (P<0.05) in the mean levels of catalase, superoxide dismutase and glutathione reductase in Groups 2, 3 and 4 when compared with the Control while lipid peroxidase showed a significant increase (P<0.05) in Groups 2 and 3. Histological observation of the cerebrum showed a normal architecture in Groups 1 and 6 while, Groups 2, 3, 4 and 5 showed degenerative changes, necrosis and clumping of cells. Conclusion: Ascorbic acid administration has been shown to ameliorate induced degenerative changes in the cerebrum caused by mercuric chloride toxicity in Wistar rats. Keywords: Mercuric chloride, Cerebral cortex, Ascorbic acid, Oxidative stress.