Canberra, Calvary, National Capital and John James hospitals will transition to a completely smoke-free environment on September 1, which will see an end to all designated smoking areas.

"Smoking kills. It is widely accepted that smoking is the leading preventable cause of disease and death in Australia so as a health authority, we want to do anything we can to make sure health premises are places where staff, patients and all of our healthcare consumers and visitors are best protected from the harmful effects of tobacco smoke," ACT Health deputy director-general Stephen Goggs said.

Mr Goggs said, unfortunately, there were still people who continued to ignore no-smoking signs.

"Obviously, we recognise that it is people's right to smoke if they choose to do so, but in the same way that a person wouldn't smoke if they went to a shopping centre or a cinema, we would ask people to remember that while they're on health premises, that's another one of those places where smoking is no longer permitted," he said.

Mr Goggs said support would be given to patients who were smokers to help them with either smoking cessation or nicotine replacement during their stay.

The move for ACT Health campuses to go completely smoke-free has been welcomed by the Health Care Consumers' Association.

"The evidence, from a public health perspective, on the damage of smoking is very, very strong, and we need to, as a community, get our smoking rates down, so we're very supportive of ACT Health policy, and we've been working with them on the implementation of the policy," HCCA executive director Darlene Cox said.

Mr Goggs said ACT Health would be increasing security, and people caught smoking would be issued with cautions.

He said fines or penalties may be considered in the future if people did not obey the bans.

Michelle Austin, director of people and culture at Calvary Health Care, said the completely smoke-free environment was a "tremendous enhancement" on work that had already been done.

"We've had a smoke-free environment policy for quite some time but this is a stronger stance around it," she said.

Ms Austin said patients at Calvary Hospital would continue to receive support not to smoke through combination nicotine replacement therapy.

"There is evidence that a combination of NRT products will increase quit rates by about 60 per cent, so, for example, it will be combining patches with gum."

She said Calvary Health Care would work hard to educate the public about why it was a necessary and important measure.