The new law comes into effect on New Year’s Day
From the 1st of January it will be illegal to smoke in a car that a child is traveling in.
Adults caught smoking in cars in which children are passengers will face fines of €100.
This rises to €150 if you do not pay within a month, with a maximum fine of €1,000 if it goes to court.
It follows the signing of regulations by the Health Minister Leo Varadkar under the Protection of Children's Health Act 2014 to bring the law into full effect.
Minister Varadkar and Children's Minister James Reilly were joined by 11-year-old Fionn O'Callaghan from Wexford, who contacted the Government to express his own concerns about the dangers of tobacco smoke in cars.
Newstalk.com's Sean Defoe reports.
Consultant oncologist and Senator John Crowne says smoking in a car with a child is a form of child abuse.
"A garda has to witness the act and that's basically it" he told Newstalk Breakfast.
"I believe it will pose some challenges in terms of policing and enforcement, but again...from day one I have always seen the primary purpose of this law being educational".
"They put it out there, it made it a subject for debate, it let people know this is an an acceptable habit - this is a form of child abuse" he added.