Over the last year, online abuse towards teachers has doubled, with 40 per cent of staff saying they had been the victims of cyber bullying by aggressive mums and dads.
That compares to 21 per cent a year earlier.
The rise is put down to the growth of social media platforms like Instagram and Snapchat.
Most remarks are either abusive, sexist, racist or homophobic and are made in relation to a teacher's looks, competence or sexual orientation.
The survey also found that 60 per cent of teachers reported derogatory comments being posted on social networks by parents and students combined, compared with 21 per cent last year.
The study, by the NASUWT teachers' union, sampled 1,500 teachers ahead of its annual Easter conference.
Chris Keates, general secretary of the NASUWT, said: "It is deeply worrying to see that the abuse of teachers has risen by such a huge margin this year.
"Equally concerning is that it appears that more parents are the perpetrators of the abuse.
"Many teachers tell us that they suspect they are being abused online but dare not look, for fear they could never walk into their school again to have to face their abusers."
The survey found that parents shamed teachers for their looks, commenting on facial features and how ugly they were. They have been called names like 'rubbish', 'bitch' and 'paedo'. They have even been falsely accused of trying to kill a pupil.
Despite the marked rise of the number of parents being offensive on social media, most comments were posted by secondary pupils, mainly using Facebook.
One teacher received vile abuse while she was heavily pregnant. Her students impersonated her on educational network Edmodo and wrote incredibly offensive remarks which made it appear as if she had written it.
The teacher said: "They then posted various comments insulting me repeatedly. A student called her an 'ugly f****** bitch'."
The survey also found that over a third of teachers had had videos or photos taken of them without their permission and posted online by pupils.