Nearly a fifth of Welsh 12 and 13-year-olds involved in a project to deter classmates from binge drinking say their parents are alcohol-dependent.
Teacher unions say parents are setting a bad example, while one expert warned that children are being more damaged by their parents' drinking than their own.
The Teenage Alcohol Project (TAP) is based on an American model of peer education and is being trialled by Cardiff university with 2,000 children from across nine secondary schools in South Wales.
TAP could be used across Wales if it proves successful. Though the results of the project will not be known until later this year, project leader Dr Lawrence Moore says that 18 per cent of the sample children had reported that their parents were alcohol-dependent, and a "sizeable number" of 12-year-olds were themselves drinking.
"Binge drinking among adolescents is a problem that has dramatically increased in the last 10-15 years and Wales compares very unfavourably to other European countries," said Dr Moore.
"Our project is a new way of looking at the problem. Getting children to advise their peers sometimes has more impact than adults - it's an idea that has worked in the past to tackle smoking among schoolchildren so we are hopeful it will also work with alcohol abuse."
The TAP project has involved going into schools and asking Year 8 and 9 pupils to select other pupils who they deem to be good leaders. The selected pupils have then been taken away for two days and given specialist training in how to deal with alcohol-related problems and how to discourage their peers from drinking.
Teacher unions believe parents are setting their children a bad example.
Geraint Davies, secretary of the National Association of Schoolmasters Union of Women Teachers Cymru, said: "Parents should also be taking up their share of responsibility for this problem and the law needs to be properly enforced to stop children getting access to alcohol.
"If we're not careful we could soon be looking at 10 and 11-year-olds abusing alcohol."
Andrew McNeill, director of the Institute of Alcohol Studies, an independent charity which provides educational information on alcohol abuse, said most children with alcoholic parents do not go on to have drink problems of their own. But they can still suffer as a result of their parents' drinking.
"More children are being more severely damaged by their parents' drinking than by their own - they are often the victims of the problem, not the problem themselves," he said.
"Having problem-drinking parents has an adverse effect on them: impaired learning at school, personality and conduct problems, attendance and truancy issues, reduced capacity for learning and health problems, including mental health.
"The children blame themselves for their parents' behaviour and tend to become isolated from other children because it's more difficult to invite them home.
"I don't suggest that teachers can act as psychiatric social workers, but they need to be sensitive to the fact that there may need to be some system set up in the school for children to talk about it."
The TAP project is due to report its full findings in September. Meanwhile, other figures suggest binge drinking among teenage schoolgirls has increased dramatically, with half of 15 to 16-year-olds now hitting the bottle each week, compared to just a third 20 years ago.
A health survey conducted in Neath Port Talbot, one of Wales's most deprived areas, revealed that many are drunk at least four times a week.
And counsellors warn that this is putting vulnerable young girls in danger.
The area's local health board, which has put together a health, social care and well-being strategy, warned that many local children were growing up victims of poor diet, increasing misuse of drugs and alcohol, and in some cases "emotional stress".
Neath Port Talbot education authority has now set up special anti-binge-drinking initiatives and is working with South Wales Police and the Youth Service to tackle the problem. Workshops, health promotion events and peer-education programmes are all being used to target teenagers.
The health survey found that though 11 and 12-year-olds are also drinking, there had been a "sizeable decrease" in the percentage of children of this age who reported doing it weekly.
Anna de Sousa, of the Gwent Alcohol Project, said alcohol often did not get as much attention as drug abuse. "Alcohol is seen as more socially acceptable and often children get mixed messages. One of our concerns is that teenagers are making themselves vulnerable to dangers such as sexually-transmitted diseases," she said.