Parents who fail to deal with their children's bad behaviour at school should be punished, teachers say.
Teachers say they are often left to 'police' pupils
Some could misuse government promises of "parent power" as an excuse to abuse staff, the Professional Association of Teachers' annual conference heard.
Many families treated schools as a "glorified crèche" and failed to instil adequate social skills at home.
Delegates voted that ministers should take "action against" parents whose children misbehave.
'Lack of respect'
Ann Nuckley, a school administrator from Bacon's College in Southwark, south London, said inspectors had found that discipline in schools was getting worse.
She told the conference in Buxton, Derbyshire: "Poor parenting fosters lack of respect and no manners.
"No wonder then that, having no guidelines, children enter education with limited knowledge about appropriate behaviour.
"Staff in education are expected to teach social skills which should have been learnt at home.
"They find themselves 'policing' classes rather than teaching."
Some parents treated schools as "a glorified crèche", she added.
Tony Blair and Education and Education Secretary Ruth Kelly have promised to put "parent power" at the heart of their schools policies.
Ms Nuckley said some parents could "misunderstand" this idea and "quote things like the Human Rights Act at us".
Peter Morris, a teacher from Bishop Gore Comprehensive School in Swansea, spoke of "pupils fighting in the classroom, throwing computer monitors around the room".
The PAT welcomed the government's task force of head teachers to investigate how to tackle school discipline problems.