A number of distinct clinical syndromes have been described that are associated with both frontal and temporal lobes and have non Alzheimer pathology. The nosological status of fronto-temporal dementia has been a matter of controversy, in view of the clinical manifestations and distribution of the nature of histopathological change. Fronto-temporal dementias include fronto-temporal dementia, progressive nonfluent aphasia, semantic dementia, and lobar degeneration and motor neuron disease. There are two morphological forms: Pick's disease and dementia tacking neuropathology. Although most fronto-temporal dementias are sporadic, familial fronto-temporal dementia linked to chromosome 17 q21-22, which is characterized by prominent filamentous tau inclusion, is caused by multiple tau gene mutation. Filamentous deposits made of tau protein are typical for the most of fronto-temporal dementia's clinical and morphological forms.