The Neuropsychiatric Institute (NPI) is a tertiary referral unit that specialises in the diagnosis and treatment of cognitive and psychiatric disorders associated with medical and neurological illnesses. It is unique in Australia in bringing together expertise within Psychiatry, Neurology, Neuropsychology, Neurophysiology and Neurosurgery to bear upon complex diagnostic issues. The NPI offers a number of specialised programs. It is also at the fore-front of research into neuropsychiatric disorders.

The NPI is a facility of The Prince of Wales Hospital, a University of New South Wales teaching hospital, and is part of the Division of Psychiatry of the South Eastern Sydney Area Health Service.