Nearly 90 per cent of children older than 10 have watched movies or videos over the past year that left them upset, a new study has found.
The study highlighted the need for safeguards to protect children from harmful content on television and the internet, said the Broadcasting Standards Authority.
The study found 32 per cent of children who watched harmful videos learned bad words, 20 per cent had nightmares or sleeping troubles, 19 per cent imitated aggressive behaviour and 15 per cent engaged in inappropriate behaviour for their age.
Children said they were most upset when seeing videos of animal torture and sex scenes.
Parents, meanwhile, worried most about children being exposed on the internet to pornography, paedophiles, bullying and strangers.
Yet - on the positive side - parents and caregivers were more proactive in setting rules for children.
These included 77-80 per cent supervising children while they watched television or used the internet, compared with 17-26 per cent in 2014 when the study was last undertaken.
"It is challenging for children to navigate the wide range of content that is now so easily accessible to them," BSA chief executive Belinda Moffat said.
"This is why classifications, parental locks and filtering software are so important."
Moffatt said it was important for authorities to continue encouraging parents to make more use of parental locks and filtering software.
When it came free-to-air television viewing, the BSA recently introduced updated safeguards in May.
They included programme classifications, warnings and the 8.30pm watershed, while the
www.safeviewing.co.nz website was launched with information for parents such as a guide to using parental locks.
Moffatt said it was not just adults who took notices of programme classifications - with 51 per cent of kids using classifications and 47 per cent heeding TV warnings to know the upcoming show wasn't suitable for them.
Parents also played a big role in talking to kids about harmful content.
About 90 per cent of children who had watched harmful videos said they felt better after talking to an adult about what had upset them, the study found.
The BSA research in partnership with NZ On Air was not only undertaken to find ways to protect children, it also sought to find out what children liked so as new shows could be better designed to entertain them.
Cartoons were the most popular shows among children followed by comedies and dramas.
Children liked shows that made them laugh the best with The Simpsons and Teen Titans the most popular.
What Now and Fanimals were the best known Kiwi-made shows.