The research, involving nearly 500 New Zealand primary and intermediate school children, showed that just educating children about the risksof excessive sun exposure was not enough to ensure sun-smart behaviour by them.
Pro-tanning attitudes among children and among their friends and families also needed to be targeted, researchers said.
In New Zealand, incidence rates of melanoma, a malignant form of skin cancer, are among the highest in the world.
Childhood sunburn is associated with a subsequently higher melanoma risk.
The national study, focusing on year 4 and year 8 school pupils, the latter aged about 12, found that older children knew more about the risks, but their attitudes and behaviour in the sun were much less protective than those of their younger, less knowledgeable peers.
The findings were published in the Journal of Paedi-atrics and Child Health.
The study involved surveying children from 27 New Zealand primary schools, including in Otago-Southland, during the summer of 2004-05 regarding their sun-related knowledge, attitudes and behaviour.
One-third of children reported that their friends thought that a suntan was a good thing, with a quarter reporting similar views among family members.
Many more female pupils reported sunbathing regularly, compared with their male peers - with nearly twice the level (29.1%, compared with 15.3%) at year 4, and nearly three times the level at year 8 (36.4%).
Study co-author Dr Tony Reeder said many children had reasonable knowledge about sun protection and skin cancer, but there were concerns about aspects of what they knew.
Dr Reeder, director of the Cancer Society's social and behavioural research unit at the university, said it was worrying that a quarter of the children considered it safe to get sunburnt once or twice a year and almost two-thirds reported having been sunburnt the previous summer.
This was despite nearly two-thirds agreeing that avoiding sunburn was a good way to reduce skin cancer risk.
Children received not only safety information but also "contrary messages" in their environment, including advertisements for sunbeds.
"You can have the information, but if you don't have the right sort of attitudes, you don't get the results," he said.
Paper co-author Dr Caradee Wright, of South Africa, said the findings indicated that attitudes of children and those who influence them should be "specifically targeted" when designing skin cancer prevention programmes aimed at influencing the sun-related behaviours of children.
