Disorders of speech and language are commonly associated with dementia syndromes, and characteristics ofverbal output can aid in the differential diagnosis of dementia and in clinical staging of dementing diseases. The cortical dementias such as Alzheimer's disease and Pick's disease are associated primarily with disturbances of language function. The subcortical dementias such as Parkinson's disease and progressive supranuclear palsy affect the motor aspects of speech, while sparing lingulstic abilities. Patients with vascular dementias and posttraumatic encephalopathies usually have dysarthria with variable language abnormalities. Metabolic encephalopathies with dementia have incoherent verbal output with non-aphasic misnaming. Speech and language rehabilitation in dementia is little explored. Treatment strategies directed toward augmenting attention and comprehension and simplifying conversation will improve communication skills between the demented patient and the care-giver.