Rosemary Gallagher, a solicitor at the centre, said: "The perception is that a teacher is the last person a child would go to with a problem."
The centre's advice line takes about 12 telephone calls a day on under-age sex, the police, drugs, alcohol and family splits. In many cases children have not known where to turn for help.
Pupils from rural and urban areas were asked who they would approach for confidential advice. Of 54 questioned, 42 said they would speak to a friend, 32 said they might also talk to their parents, but only seven would go to a teacher. One said: "If they're going to tell someone else then that's not what I want."
Guidance teachers often face a dilemma if they are told about an illegal activity.
"There is a need to get a balance between giving a child the confidentiality they want and protecting them. Teachers are not bound by the law to disclose the information," Miss Gallagher said. Where disclosure is necessary, the child should be informed.
Miss Gallagher is currently carrying out research into young people's access to legal advice, funded by Children in Need