Hospitals in Liverpool are banning all visitors, staff and patients from smoking in their buidings and grounds.
Smoking rooms have been closed down
The Royal Liverpool and Broadgreen Hospitals NHS Trust will enforce the decision on National No Smoking Day.
Smoking rooms have been closed, smoking shelters have been taken down, and the trust will offer help and advice to those who want to give up smoking.
Brian Goodinson, of the trust, has said patients could always choose to be treated elsewhere.
"We will give them whatever support it takes to give them the opportunity to stop smoking while they are with us," he said.
The trust includes the Royal Liverpool University Hospital and Broadgreen Hospital.
By the end of the year all hospitals on Merseyside will be smoke-free.
Councillors have voted in favour of a private bill to make Liverpool the first smoke-free city in the UK.
Under the ban smoking would be banned in restaurants, pubs, shops, offices and enclosed workplaces.
The bill will get a second reading in the House of Lords on Friday. If the bill progresses it could be law by next year, unless it is superseded by new government anti-smoking laws.