By Justin Parkinson
BBC News education reporter at the NAHT conference
Teenagers and parents who make malicious allegations against teachers should face legal action, a union says.
Head teachers say those making false claims should face action
Even staff who are not taken to court face "public humiliation", the National Association of Head Teachers heard.
Michael Murphy, a head teacher from Wolverhampton, said the teaching profession was "paralysed by fear" of false accusations.
Delegates at the union's annual conference in Harrogate voted unanimously to back legal action.
The motion called for an investigation into ways of dealing with "a young adult, or a member of their family, who make a clear-cut, provable, malicious allegation".
Mr Murphy, head of Corpus Christi Primary School, said that every accusation should still be investigated.
However, in cases when the Crown Prosecution Service decided not to take teachers to court, they had to face parents' and children's suspicions upon returning to the classroom.
Mr Murphy said: "The perpetrator walks away without accountability.
"This cannot be right; this cannot be fair; this cannot be just."
He added: "The pendulum has swung too far. All we want is balance, fairness and freedom from fear."
On Sunday, Shadow Education Secretary David Willetts received applause from NAHT delegates when he called for teachers accused of abusing pupils to have a legal right to anonymity.