The fall in 2003 occurred after junior education minister Ivan Lewis urged schools to sign anti-bullying charters and take a "zero tolerance" stance against bullies.
Zurich Municipal, which insures the greatest number of schools in Britain, reported this week that bullying claims fell by 75 per cent in 2003, dropping to the lowest level for five years.
Until last year there had been a steady rise in cases where parents had sued schools for failing to tackle bullying of their children.
Alan Hunter, technical claims manager at Zurich Municipal, said the figures suggested that the national campaigns against bullying were starting to take effect.
"It appears that the initial flood of claims for bullying has been largely unsuccessful due to some strong judgments from the courts and the implementation of strict anti-bullying policies in schools across the UK," he said.
He said that schools should keep their anti-bullying policies at the forefront of teachers' minds.
The Government has funded a pound;60,000 advertising campaign urging children to "Tell Someone" if they have a problem.