"You never expect it to happen and when it does, it's a shock," Dennis Yarrington says.

More than one in three principals experienced physical violence at school in 2016, according to the country's largest survey of principal health. This is up from 27 per cent the previous year.

And a staggering 44 per cent of principals were threatened with violence.

Fortunately Mr Yarrington, who is now the president of the Australian Primary Principals Association, narrowly avoided the punch that was thrown at him at a Canberra school three years ago.

A few months later a parent stood very close to him, shouted in his face and threatened him. The parent then took to Facebook to defame him because he didn't like one of his decisions.

"It starts to impact your sleep, you start to think 'should I come to work?'," he says.

Mr Yarrington, who has worked in ACT and NSW schools, is deeply concerned about the deteriorating health of principals.

"We are saying enough is enough. We have to stop this," he says.

The latest Australian Principal Occupational Health, Safety and Wellbeing Survey, which was completed by more than 3000 principals and is now in its sixth year, identified high levels of stress and burnout in the profession.

One in 10 principals had thought about self-harm in the past week or indicated that they had a very poor quality of life.

Report author Philip Riley, an associate professor at the Australian Catholic University, said offensive behaviour occurred in schools in all sectors.

"The myth is that this sort of offensive behaviour occurs in poor government schools. That's not true. It happens everywhere," he says.

The violence ranged from hitting or kicking to more serious incidents which have led to principals being hospitalised.

In one case, a private school parent who was a barrister pinned a principal against a brick wall, pushing his elbow against his throat, over a dispute about fees.

In primary schools, parents are the main perpetrators of violence against principals, and in high schools, students are the main offenders.

Principals experience burnout rates that are 1.6 times higher than the general population and stress symptoms that are 1.7 times higher. This stress is caused by the sheer quantity of work, resourcing needs and not having the time to focus on teaching and learning.

Mental health issues in the profession are being closely examined following the death of respected Melbourne principal Dr Mark Thompson, who took his own life in 2014.

Professor Riley said private school employers, Catholic education offices and state governments were not doing enough to tackle the problem. He called for long-term initiatives to address the issue including an independent authority to investigate adult bullying, threats of violence and violence in schools.

Australian Education Union federal president Correna Haythorpe said providing more resources to schools would reduce stress.

"Being a principal will always be a difficult and challenging job, but we can reduce some of this stress by making sure all schools have the resources they need," she says.

Australian Institute for Teaching and School Leadership chief executive Lisa Rodgers said being a principal had become a much more complex job.

"There's more and more pressure to deliver and people are expecting a quicker response to things, in an area where there is quite a bit of conflict," she says.

She said reducing red tape, and ensuring there was social cohesion and collaboration in schools would ease stress and violence in the profession.