Six in ten of teachers say they have considered quitting over bullying by managers and colleagues.
The findings, by the Teacher Support Network, were revealed on Ban Bullying at Work Day, today.
The organisation found 47 per cent of teachers and college lecturers considered quitting due to management bullies.
A further 12 per cent said colleagues had given them trouble and one per cent mentors or governors.
Patrick Nash, chief executive of the Teacher Support Network, said: "Bullying in schools is not confined to the playground.
"Staffroom bullying is a very serious matter which must be tackled by managers in schools, colleges and universities before teachers and lecturers quit due to stress, depression and anxiety.
"Relationships with managers and colleagues really impacts on the enjoyment and development of teachers and lecturers.
"Unfortunately, bullying has a destructive effect on the confidence, morale and health of the bullied person, and potentially has a knock-on impact on their students."
According to Mr Nash, bullying took many forms from relentless criticism and fault finding to excessive work expectations and blocks to promotion and training.