A Brisbane principal has warned that parents who send derogatory emails, or abuse teachers on social media, will be reported to the Department of Education.

Key points: The Gap State High School principal wrote a stern warning to parents over online abuse last month

The Gap State High School principal wrote a stern warning to parents over online abuse last month According to the memo, the abuse has been ongoing for the past 12 months over a change in the school uniform policy

According to the memo, the abuse has been ongoing for the past 12 months over a change in the school uniform policy In 2018, the school issued detention to about 100 students for not wearing the correct uniform

The Gap State High School Principal (TGSHS), Anne McLauchlan, said the online abuse had reached "unacceptable" levels, in a newsletter sent to parents last month.

"I have reflected on the incidents of abuse my staff and I, as principal, have endured at the hands of a minority of parents," she wrote.

"Nearly every one of these incidents involved social media or email. On two occasions, parents have been directed off the grounds due to their hostility."

The online abuse has been ongoing over the past 12 months, according to the principal's memo to parents.

Queensland Teachers' Union president Kevin Bates said it was prompted by a change in the school uniform policy, early last year.

TGSHS issued detention to about 100 students in February last year, for not wearing the correct uniform, including the wrong-sized heel on their school shoes.

"It caused a fair bit of media attention when parents at the school took to social media to criticise the school, but did so in a way that was completely inappropriate, and that led to the issues," Mr Bates said.

"Teachers and students have a right to expect that school will be a safe place."

The school has urged parents to "arrange a face-to-face appointment to discuss grievances." ( ABC News: Shelley Lloyd )

In the memo sent to parents on February 22, Ms McLauchlan urged parents to "arrange a face-to-face appointment to discuss grievances".

"If you feel you are too busy to find the time for a meeting then I would question the importance of the complaint," she said.

"In the case of derogatory, insulting and unsolicited social media posts about staff, the materials will be reported to the State Government's Information Services branch for investigation."

Mark Breckenridge from the Queensland Secondary Principals' Association said teachers also have the right to report serious allegations to police.

"They have the same recourse in terms of making a complaint should a parent become physically hostile," he said.

Mr Breckenridge said he was aware of several other school principals facing similar issues.

"People can sit behind a keyboard or on a phone and send off into social media all sorts of claims and accusations and make threats in the comfort of their own homes," he said.

A national survey, released last month by the Australian Catholic University, revealed one in three principals have experienced violence at school — half said they had been bullied and intimidated.

Mr Bates said the issue had reached a national level, but "extreme" examples had been witnessed in Queensland.

"We've seen in cases over the last few years, schools on the Sunshine Coast with principals and staff receiving death threats over placing a ban on students doing cartwheels in the school ground right through to this particular incident," he said.

The ABC contacted TGSHS for comment but was referred back to the Education Department.

Queensland Education Minister Grace Grace said teacher abuse was an ongoing issue and the government had committed approximately $140 million to safeguarding the wellbeing of school principals across the state.

"Everyone should treat everybody with respect at all times, value their independence … and stop any form of bullying … that's our main aim," she said.

"The Premier has put this issue on the national agenda."

Deputy Opposition Leader Tim Mander said parents needed to be better role models for their children.

"We do have to stamp this out — it's inappropriate and our teachers have enough pressures without being bullied," he said.