Smoking levels among adults in Northern Ireland have not reduced in the last five years, the health minister has said.
Almost a quarter are using tobacco and one in two will die early from the habit, health experts added.
Minister Edwin Poots was launching a new tobacco control strategy.
"Smoking remains the single greatest cause of preventable illness and premature death in Northern Ireland and is the leading cause of health inequalities in our society," he said.
Smoking prevalence among adults has remained around 24% since 2007 and for manual workers that rate is 31%.
Mr Poots added: "Clearly we still have some way to go before we achieve the substantial reductions we are seeking with regards to smoking prevalence."
In Northern Ireland, 340,000 people aged 16 and over smoke and one in every two will die early because of it, according to experts from the Public Health Agency.
The Ten Year Tobacco Control Strategy for Northern Ireland aims to reduce the numbers taking up smoking, to encourage more to quit and to afford greater protection for the whole population from tobacco-related harm.
The Executive has introduced smoke-free legislation in public areas such as the workplace, bars and restaurants. It has increased age requirements and developed smoking cessation services. There are also measures to scrap vending machines and remove displays of cigarettes in shops.
Mr Poots said: "My overall policy aim is the creation of a tobacco-free society in Northern Ireland. It will obviously take a long time to achieve this but it is not impossible when you see the progress that has been made in places such as Australia and California."