Around 157,000 children between the ages of 11 and 15 start smoking each year in the UK - the equivalent of 5,200 classrooms.
The figures, produced by Cancer Research UK, also reveal that more than a quarter (27 per cent) of under-15s have tried smoking.
With eight out of ten smokers starting before their 19th birthday, the figures highlight the need for schemes that discourage youngsters from trying cigarettes.
Cancer Research UK believes that introducing plain packaging for tobacco products could help to prevent people from starting to smoke, as the measure would make cigarettes less attractive to children.
Jean King, the charity's director of tobacco control, claimed: 'The tobacco industry spends a great deal of money on designing cigarettes and their packets so they seem glamorous, appealing, fashionable and attractive in an effort to recruit more customers.
'With advertising outlawed, the cigarette packet is now the most important marketing tool the tobacco industry has.'
Earlier this week (February 20th), charities criticised a new report from the Adam Smith Institute, which claimed that putting cigarettes in plain packs would have no benefit for public health.
Action on Smoking and Health argued that the think-tank had misrepresented the truth and was 'acting as the mouthpiece for the tobacco industry'.