Smoking in pubs, restaurants and other enclosed workplaces in Ireland will be banned from 29 March, the government has announced.
Pubs fear they will lose customers
Health Minister Michael Martin said he hoped the ban would contribute to protecting the health of the nation.
"Quite frankly, people should not have to be unwillingly exposed to this toxic substance," he said.
There has been strong criticism of the ban from Irish publicans, and a group of them have pledged to ignore it.
Pub owners say it will be impossible to enforce, especially on busy weekend nights.
They have asked the government to allow for special smoking sections, but were rejected.
But some bars in the capital, Dublin, appear to have accepted the ban.
They have already begun setting up wall-mounted ash-trays outside their premises as well as heated outdoor areas for smokers.
The ban will not apply in hotel rooms, prisons, nursing homes and psychiatric hospitals.