Plans have been unveiled to dramatically reduce smoking levels in Wales with the ultimate goal of a "smoke-free society".
Playgrounds and all NHS property could be made smoke-free zones, as the assembly government aims to reduce smoking levels to 16% by 2020.
Around a quarter of adults in Wales smoke.
The chief medical officer also wants to start a "debate" on smoking in cars carrying children.
Dr Tony Jewell said: "Just as Wales took a bold step in creating smoke-free environments in public places, we recognise that the time is right to champion new approaches to further protect children from the harms of second-hand smoke.
"The plan proposes that local authorities will be encouraged to introduce smoke-free policies for playgrounds and to initiate a debate on smoking in cars carrying children.
"The NHS should set an example when it comes to creating smoke-free environments and supporting staff to quit smoking.
"The NHS should also encourage patients to stop smoking, particularly before elective surgery."
Wales brought in a ban on smoking in enclosed public places in April 2007.
The assembly government does not have the powers to ban smoking in cars with children but is keen to raise the issue.
Its new plans are outlined in a consultation to reduce smoking and exposure to second-hand smoke.
Proposals include lobbying the UK government on issues such as increasing the price of tobacco through taxation, and continuing to discourage children from smoking.
The consultation says smoking continues to be the largest single preventable cause of ill health and premature death in Wales, causing around 5,650 deaths each year.
Dr Jewell wants to protect children from second-hand smoking at home and in cars after speaking out on the issue last year.
"Reducing children's exposure to second-hand smoke will help to protect the most vulnerable in society and promoting smoke-free cars carrying children will bring home to parents the risks of smoking in front of their own children," he said.
"Children are not able to protect themselves from this exposure and it must be shown to be a serious public health risk through the development of legal protections, where appropriate, and policy initiatives."
Simon Clark, director of smoking rights pressure group Forest, said he would be "strongly opposed to any further restrictions on smoking in public places".
"There is no justification on health grounds for banning smoking in the open air. To ban smoking in hospital grounds would be very unfair on patients, staff and visitors," he said.
"The war on tobacco has gone far enough. I'm sure the Welsh assembly has better things to do than to target smokers."
Anti-smoking charity Ash Wales welcomed the proposals.
"This is an historic day for public health in Wales and the best news since the smoking ban was introduced in 2007," said Ash Wales chief executive, Tanya Buchanan.
"The action plan is the first such strategic plan for Wales which aims to systematically address smoking prevalence rates which have stagnated at 24%, and ensure our young people are protected from second-hand smoke."