Brentry was once well known for its hospital, founded in 1898 as the Brentry Certified Inebriate Reformatory.
In 1922 it became an institution for the mentally ill, and was renamed Brentry Certified Institution. It was renamed the Brentry Colony in 1930. In 1948, under the National Health Service, it became Brentry Hospital. It closed in 2000.
Brentry House, a grade II listed building built in 1802, was used as the administration building for Brentry Hospital. This building was designed by James and Humphry Repton. Now known as Repton Hall, it has been converted into residential apartments.
The hospital site now forms a major component of the Brentry Conservation Area.