Background: Monosodium Glutamate (MSG) is one of the most widely used food-additives in commercial foods that had effect on various tissues including cerebellum. It acts via creating an oxidative stress. The central nervous system is a target organ for MSG especially cerebellar cortex. The health benefits of vitamin C were derived from its role in the key reactions within immune function, metabolism, and other enzymatic reactions. Aim: To evaluate the effect of MSG on rat's cerebellar cortex with the possible protective role of Vitamin C. Methods: Twenty one adult male albino rats have been used in this work. The animals were randomly divided into three groups with seven animals in each group. Group 1 (Control): Animals were kept without addition of any chemicals. Group 2 (MSG-treated): Animals were subjected to administration of MSG ‎4g/kg body weight dissolved in 1 ml normal saline. Group 3 (MSG and Vitamin C treated): Animals were subjected to administration of both MSG ‎4g/kg body weight dissolved in 1 ml normal saline and 500 mg/kg vitamin C, orally. By the end of the experiment which was 10 days. Animals were anaesthetized and sacrificed. Cerebellar hemispheres were obtained and specimens were processed for both light and electron microscopic examination. Results: MSG caused histopathological and morphometric changes in rat's cerebellar cortex. Vitamin C protected the cerebellar cortex specimens against such changes. Conclusion: MSG could result in hazards to the structure of cerebellar cortex. Fortunately co-administration of vitamin C is suggested to reduce such hazards.