Girls as young as 11 are “trying and buying” e-cigarettes, public health officials have warned.
A survey carried out in north Wales found that most could name five vapour flavours, and some did not know e-cigarettes could contain nicotine.
The girls were using e-cigarettes to cope with stress, because their friends smoked, because they felt it “looked cool” or to help them lose weight.
More than 1,100 girls took part in the Social Change UK survey, carried out for Public Health Wales.
Measures to control the sale of e-cigarettes to under 18s are being developed with trading standards.
Report author Kelly Evans told BBC Wales: "Overall, young girls were telling us cigarettes were yucky, not nice but that e-cigarettes are better for you or not as bad than cigarettes.
"They're attracted to the different flavours and are trying them and have access to them.
"Ever since the tobacco companies have come into the market the number of flavours is increasing on daily basis. Why do we need 300 flavours? If they're just a smoking aid for adults, why do we need a gummy bear flavour?"