The hospital stands next to the Children's Hospital, and has provided public hospital care to adult patients for more than 150 years. It was established by the Sisters of Mercy as a Roman Catholic voluntary hospital within the health system of the Republic of Ireland.
The Mater Hospital is a tertiary referral centre for cardiothoracic surgery as well as housing the National Spinal injuries unit. It also houses the national heart and lung transplant programme. The National Pulmonary Hypertension Unit is also the leading centre in this area in Ireland. It also is a major centre for cardiology offering the only 24 hour, 365 days per year interventional cardiology service in the country. It is also expected to be the first public hospital in Ireland to offer percutaneous heart valve replacement in the coming weeks. It offers regional dermatology and opthalmology service. As well as nephrology, neurology, respiratory medicine, endocrinology and diabetology, GI medicine and hepatology and infectious diseases, which contains a new multi million euro negative pressure ventilation ward to house the national bioterrorism unit.
The existing hospital facility is expected to be renovated and to include a new maternity unit.
The Sisters of Mercy are required to donate the site for this hospital to the State, unencumbered and without compensation. The order had understood that the new facility would be owned by the State and its management vested in a company independent of the nuns. The nuns, as landlords, would have expected representation on the board of the management company and to have been in a position to enforce a Roman Catholic ethos.