The history of health service in western Sydney began with a tent hospital established in Parramatta to meet the medical needs of convicts, military personnel, and early settlers in 1789.

[5] As population expanded in Sydney's west, the services provided at Parramatta became inadequate to meet demand.

[citation needed] The hospital was the first major tertiary referral health centre in outer Sydney.

Parramatta Community Health Centre, located in Jeffery House, still operates on part of the original site.

[2] In 2004, a contract worth in excess of A$142 million[8] for refurbishment and development of new facilities at Westmead Hospital was awarded to Thiess.

In March 2012, a food-court style emporium was opened on the ground level precinct introducing a wide variety of cuisines to the standard hospital fare, including a sweets and desserts cafe, kebabs, pizza, fresh salads and sandwich bar, gelato station, and various selections of hot foods.

[15] Westmead Hospital is the base for the New South Wales helicopter operations of CareFlight air ambulance service.

Within Westmead Hospital exists the Trauma Service, which provides research and education of injury prevention, and death statistics.

The University supported the establishment of research clinicians in all key staff specialist postings at the hospital in 1978.