Northern Ireland footballer David Healy is urging people to give up the habit.
David Healy wants smokers to give up
On the day when the smoking ban came into force, the Leeds striker called on people to go one step further and give up smoking completely.
David was responding to a survey of 125 seven to fourteen-year-olds in Northern Ireland which showed 97% of children whose parents smoke want them to stop.
"The main dangers that people are worried about now is that smokers take it home to their kids," he said.
"The best thing to do is stop smoking. It is not going to be easy but that is why I am here today and if one in a few people stop, hopefully that helps."