Move includes GP practices
Noble's Hospital will go smoke-free from 1 April.
The habit will be banned on the grounds and in the car parks.
It will also be prohibited at a number of other hospital sites, GP practices, facilities at Westmoreland Road and the health department headquarters at Crookall House.
All other premises operated by the Department of Health and Social Care and Manx Care, aim to be smoke free by April 2022.
Health Minister David Ashford says the new policy will rely on public cooperation:
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