Monosodium glutamate is white-crystalline substance commonly used as a flavour enhancer. However, concern has been raised on its untowards effects on the cerebellum and various of organs of the body. The histology of the cerebellum sections from rats in the different treatment groups that were characterized by degenerative, necrotic and inflammatory changes in this study might be an indicative of onset of toxic stimulus of monosodium glutamate in the cerebellum. Some effects have also been adduced in this book to explain the harmful effect of this flavour enhancer on health. This book is therefore designed to enlighten the readers to understand the deleterious effects of monosodium glutamate on cerebellar cortex.