Lewy bodies (LB) are intracystoplasmic eosinophilic hyaline inclusion bodies associated with progressive neuronal degeneration. Immunocytochemical techniques have identified two proteins in the core of LB, ubiquitin and alpha beta-crystalin, which are thought to be involved in cytoprotective mechanisms. LB are diffusely distributed throughout the brain, brainstem and cerebral cortex, and are commonly associated with neuro-degenerative diseases. The article includes some cases in literature to study the diffuse Lewy body disease, senile dementia of the Lewy body type and Lewy body variant of Alzheimer's disease.