NHS Greater Glasgow and Clyde launched a tough crackdown on smoking at the main troublespots - hospital entrances - earlier this year.
And while the board admits the issue won't be solved overnight, figures show a marked drop in smoking by patients, visitors and staff.
The board carried out a check at the city's biggest hospital, the Royal Infirmary, before and after the pilot was introduced.
During one hour in February, 100 people flouted the existing no-smoking policy outside the hospital's Alexander Parade entrance.
A similar check in July, weeks after the crackdown was introduced on May 13, found the number of people smoking had dropped to 40.
Across all 11 NHSGGC sites, the figure had almost halved from 404 to 208.
At some hospital entrances - Vale of Leven and Stobhill - no one was caught smoking during the test hour.
At Yorkhill Hospital, where young patients designed artwork to deter smokers, the number of visitors being approached about their smoking went from 324 in July to 181 in August, a reduction of 44%.
The board also collated the responses of 10,000 smokers and said 90% had reacted positively when they were asked to put out their cigarettes
Soon after the campaign was launched, three wardens quit their jobs because of abuse they were getting when asking smokers to stub out their cigarettes.
Wardens now say smokers are displaying far less aggression when asked to stub out their cigarettes or move on.
The board is now looking to extend no-smoking zones, and will also target health centres.
Fiona Dunlop, Smoking Cessation Lead, said: "Prior to the crackdown people were not adhering to the no-smoking policy.
"The figures show this has dropped significantly.
"The Royal is the biggest hospital and that entrance (Alexander Parade) in particular has been problematic.
"The number has reduced across all sites.
"Initially, people were very unhappy at being asked to move they are now expecting to be moved on.
"A major part of the campaign is enforcement and the wardens are key to that.
"Staff feel more confident about asking people not to smoke, because of their presence.
"This is about changing social norms. It's about the social acceptability of smoking on a health site.
"We appreciate that being in hospital is stressful and might not be the best time to quit.
"What we need to do is change the culture, it's always been acceptable for patients to go out but now they have to leave the grounds to smoke."
The Scottish Government has placed a requirement on hospitals to be smoke free by 2015, however it has stopped short of introducing legislation.
The no-smoking policy also includes e-cigarettes, .
Staff have also been told they will face disciplinary action for repeated breaches of the ban.
Stuart Montgomery, 23, from Muirend, has been working as a warden at the GRI for two months.
He said: "In the beginning, there was a lot of people saying, 'it's not the law', you can't do anything to me'.
"I now know how to speak to people."
Jim Murdoch, 60, from Knightswood, said: "I've seen a big difference since I started.
"I was in security for ten years. If you go in all gung ho that just antagonises people. I think it helps to have a younger warden and a older one.
"It's a challenge but this is only the beginning."
All smoking shelters were removed from NHSGGC hospital sites some time ago, aside from those that are only accessible by patients in mental health wards, as is required by law.
Other health boards are now said to be considering adopting measures being used by NHSGGC.
Ms Dunlop said: "It's a challenge for every board. Everyone is looking at what we are doing.
"Legislation would be helpful, to have some power of enforcement.
"This is going to take time, short term measures are not going to work."