Children as young as 12 should receive nicotine patches if they have a serious smoking problem, the official NHS advisory body in England says.
The age at which cigarettes can be bought has been raised to 18
The recommendation comes in a set of guidelines by the National Institute for Clinical Excellence (NICE).
These are intended to advise health authorities on helping people give up smoking.
Children have been offered patches in trials, but this is the first time it has become official English policy.
The guidelines set a target for the number of people who should be treated each year.
According to NICE, adults should be offered nicotine replacement therapy (NRT) such as patches and gum, and drugs like varenicline and buproprion, as well as counselling and group therapy.
Those under 18 should not be offered drugs - nor should pregnant women, it says. But those aged between 12 and 17 should be provided with information, advice and support, and NRT "when there is clear evidence of nicotine dependence".
Late last year, the legal minimum age at which tobacco can be bought in England, Scotland and Wales was raised from 16 to 18.
Some 9% of 11 to 15-year-olds smoked prior to the move, but it is as yet unclear how the change has affected that.
NICE guidance is not binding on the NHS, but it carries much weight.
Primary Care Trusts and Strategic Health Authorities should aim to treat at least 5% of their population who smoke each year, and to aim for a success rate of 35% having given up after four weeks, it says.
The NHS Stop Smoking Services should also make a beeline for ethnic minority and socioeconomically disadvantaged communities in the local population, the guidelines state.
Tobacco use, the body noted, was "the primary reason for the gap in healthy life expectancy between rich and poor".
"Smoking is still the main cause of preventable morbidity and premature death in England," said Professor Peter Littlejohns, clinical and public health director of NICE.
"Most smokers want to quit and in this guidance we aim to ensure that the right services are put in place to help them to stop."
Anti-smoking group ASH welcomed the new policy, noting that "smoking cessation is one of the most cost-effective forms of health intervention".
"The guidance is also important in recognising that many young people need help in stopping smoking," said director Deborah Arnott.
"Addiction can occur very quickly after starting to smoke and young people deserve the same level of support in quitting as older smokers."