Dublin City Councillors have voted in favour of "No Smoking" signs in council-managed playgrounds.
The motion was proposed by Labour Cllr Steve Wrenn, who works as a HSE child protection officer and has a qualification in smoking cessation.
He said that allowing children to be exposed to second-hand smoke now constitutes neglect according to HSE guidelines.
Mr Wrenn said he was not proposing to bring in by-laws but to have "No Smoking" signs put up.
Fine Gael Cllr Gerry Breen disagreed with the motion and said it would bring the council into disrepute by putting up signs "banning something that isn't banned".
Other councillors said it would be unenforceable.
However, City Manager John Tierney said such signs are part of council plans and act as a discouragement, although there will not be any prosecutions.
The motion was agreed by councillors after a proposal to include sporting areas was dropped.