More than half of school-aged drinkers who responded to a University of Auckland survey said their parents buy alcohol for them.
The university's second report on the health and wellbeing of secondary students found that while drug use is declining, binge drinking remains a serious problem.
Seven years after the last report, the number of young people who smoke or suffer from depression has fallen, but a third of young people continue to binge drink.
Paediatrician Simon Denny who conducted the research said parents are giving their children conflicting messages by buying alcohol and then criticising them for drinking.
Dr Denny said parents are probably trying to create a safe drinking environment for their children.
Alcohol Advisory Council chief executive Gerard Vaughan said the best thing parents can do is to try to delay the age at which their children start drinking.