A headteacher has been doorstepping pupils' homes to confiscate TVs and computer games from their bedrooms so they get to sleep at a reasonable time.
Duncan Harper, head of New Woodlands School in Bromley, south London, took the radical approach because some pupils were too tired and irritable to concentrate in class.
The children's behaviour and test results have improved dramatically as a result of the school's tough line, Mr Harper said.
The policy emerged after complaints from headteachers that too many parents were afraid to say "no" to their children and send them to bed at a reasonable time.
Woodlands is a special school for children aged between five and 11 with behaviour problems, many of whom have been excluded from mainstream schools.
"We were noticing that there were a lot of children coming in absolutely shattered," Mr Harper said.
"Some of the younger ones were falling asleep, literally, in the classroom.
"When we looked into it the majority had televisions and Play Stations in their bedrooms."
He said some "very young" pupils were playing games classified as suitable only for 18-year-olds.
With the backing of the parents, Mr Harper and his deputy head visited the homes of children who were behaving poorly and removed their televisions or computer games.
"We make it quite clear in a little contract what they have to do to earn it (the television) back. It has been highly successful."