A series of hard-hitting government adverts featuring people smoking cigarettes with a tumour growing from the end is being launched in England.
The ads will tell smokers that just 15 cigarettes can cause a mutation that leads to cancerous tumours in what marks a return to shock campaigning.
It is eight years since government's "fatty cigarette" anti-smoking adverts appeared.
This £2.7m ad campaign will appear on TV, online and posters until February.
Smokers will also be told about NHS quit kits that are available free from pharmacies.
More than a third of smokers still believe the health risks from smoking are greatly exaggerated, recent statistics from the Department of Health showed.
Chief medical officer Prof Dame Sally Davies said smokers were still underestimating the serious health risks from smoking.
"We want smokers to understand that each packet of cigarettes increases their risk of cancer."
"People will see a man smoking and then a cancer growing out of the cigarette. That is what happens in people's bodies.
"We really want to catch all smokers but particularly the young who won't have seen hard hitting campaigns before. They don't understand what damage is happening in their bodies, what their risks are," she added.
The adverts follow the Stoptober campaign, which saw more than 270,000 sign up in a mass attempt to quit two months ago.
The ad campaign has received the backing of Cancer Research UK.
Its chief executive Dr Harpal Kumar said: "Hard-hitting campaigns such as this illustrate the damage caused by smoking and this can encourage people to quit or may even stop them from starting in the first place."
"Giving up smoking can be extremely difficult, so providing extra motivation and reminding people of just how harmful the habit is can help smokers to take that first step in quitting for good."
The charity said smoking is the single biggest preventable cause of cancer and causes about a quarter of all cancer deaths.