Currently just two per cent of child witnesses in criminal court cases receive guidance on criminal proceedings from registered advisers, the NSPCC findings reported, and yet at least half said they were unable to understand some of the questions they had been asked.
The research showed that more than 50 per cent of child witnesses reported symptoms of stress ahead of a trial, including panic attacks, self-harm and difficulty sleeping.
Children giving evidence in court in sexual abuse cases need to be given more support, with many suffering from stress ahead of a trial, the NSPCC has said.
The children's charity warned some cases are collapsing because not enough is done to help vulnerable witnesses, it has been reported.
Fewer than a quarter of the 23,000 child sex offences recorded in England and Wales last year resulted in prosecution, according to the NSPCC.
Chief executive Peter Wanless told the BBC news website: "These children have to publicly relive the most traumatic, upsetting and humiliating experience of their lives in order to try and get justice."
The number of calls made to a charity helpline reporting sex abuse this summer has been "significantly higher" than last year, the head of NSPCC helpline said today.
John Cameron said that the Jimmy Savile scandal is "changing the way in which people react to abuse".
"There appears to be a clear shift and the public now seem better equipped and more confident to report their concerns.
"The Savile scandal has shocked the nation but has also increased public awareness of how difficult it is for children to speak out and how crucial it is for adults to report any suspicions or concerns they have straight away."
The NSPCC's 'Talk PANTS' campaign, launching today, is being supported by Netmums and complements the organisation's ChildLine Schools Service, which is visiting every primary school in the UK advising children how to stay safe from all forms of abuse.
Peter Wanless from the NSPCC said the campaign aimed to make children more aware of what abuse is so that they can identify it and prevent it, as well as enabling children to talk to their parents about the issue.
The shocking case of Savile has horrified many parents and understandably it has heightened concerns around sexual abuse. But most abuse is closer to home and if we are to tackle this issue we must prevent it before it even starts.
To do this we must educate our children about staying safe and speaking out.
Parents are being urged to talk to their children about sex abuse in order to protect them from being victimised by potential predators.
The NSPCC has launched a new 'Talk PANTS' campaign aimed at encouraging parents to have open conversations with their children on the subject. NSPCC chief exec Peter Wanless said opening up the channels of communication was key for parents, and could "make a big difference."
Parents have told us they lack confidence in approaching this difficult but important issue. We've worked with parent groups to devise a simple, age appropriate way of making sure children speak up if something happens. It's a quick conversation but could make a big difference."
The NSPCC has launched a campaign aimed at helping parents talk to their children about sex abuse, in a bid to protect children from sexual abuse. The campaign, called 'Talk PANTS' encourages parents to teach their child five simple rules:
The NSPCC has launched a new campaign to help parents protect their children from sexual abuse. The campaign is aimed at helping parents talk to their children more to enable them to lower the risk of being victims of offending.
It comes as a YouGov poll shows that half the parents of 5-17-year-olds surveyed have never spoken to their sons or daughters about the issue.