A smoking ban in open spaces, such as footpaths, civic squares and beaches, is to be investigated by Auckland Council.
The entire central business district could also be covered by a new bylaw.
The council's regional strategy and policy committee yesterday voted to investigate the bylaw and strengthen efforts to make smoking socially unacceptable.
The measure comes in the same week it was revealed that Auckland Council has investments in British American Tobacco. The council is reviewing the investment.
Health organisations including the Cancer Society and Hapai te Hauora addressed the committee urging it to "do the right thing" and make a "landmark policy step".
Officers advised the committee that choosing the bylaw option could be legally challenged and came with associated costs.
However, Mayor Len Brown and committee chairman George Wood chose to proceed with the investigation.
Brown applauded the decision, saying the council already has the country's most comprehensive smokefree policy and the time has come to take a more proactive and regulatory approach.
Cities around the world are opting for a regulatory approach.
In Australia, several states and territories already have smokefree laws for outdoor dining areas.
While a new bylaw would take some time to develop, it could be the first major outdoor smokefree bylaw in New Zealand and - with a necessary law change - possibly empower the council to issue infringement notices which it currently cannot.