Council owned facilities will become smokefree under the policy as will council funded events.
Dr McMenamin said there were about 10,000 smokers in Whanganui with about 10 per cent engaged in stop smoking services.
"So we've got around 1000 smokers interested in stopping smoking. On that basis you'd think we'd be able to reduce smoking quickly," he said.
"(But) the uptake is faster than we can help people quit."
Regional Health Network figures show the number of people smoking in Whanganui has increased in the past three years by 2 per cent to 19.3 per cent during a period when the national rate decreased.
Dr McMenamin told councillors that public health measures - such as price and the council policy - was the most effective way reduce smoking rates.
"Essentially we are in the business of trying to change human behaviour here," he said.
"What we are trying to do is create environments that support being smokefree, motivates people to look at quitting and reduces the opportunity to smoke."
He said that was the main reason people were asking for help to quit.
"It's not being driven because people have suddenly become aware of the health issues.
"Sometimes you need to influence the individual but sometimes we need to create situations where we make it less likely that things will happen."
Dr McMenamin said vaping, where people smoke vapour created by an electronic device, as an alternative to cigarettes needed to be treated with caution too.
"Long term there is definitely going to be some risks associated with vaping as well," he said.
"There are harm reduction benefits but there are significant health risks associated with it."
In May the council revoked its smokefree bylaw, which was not enforceable, and put the review of the smokefree policy out for consultation.