Parents are being urged to keep Christmas gadgets out of the classroom.
Gadgets like mobile phones can disrupt lessons
England's Children's Minister Kevin Brennan says electronic toys, music players and phones often appear in schools as the new term begins.
Children often bring the fascinating gadgets they were bought as Christmas presents into class, but these can cause disruption and hamper learning.
Teachers can and will confiscate such items if they see them being used in lessons, Mr Brennan warned.
General secretary of teaching union the NASUWT Chris Keates said: "Every year some youngsters arrive back at school with MP3 players, mobile phones and electronic games.
"This can be a real headache for teachers when they are trying to get everyone settled down to start learning. Teachers would be grateful if pupils just brought a pen."
Mr Brennan said many Christmas presents got broken in the first weeks of the new term or had to be confiscated by teachers because they were misused in class.
"It is rightly down to schools to decide how best to deal with electronic equipment being brought in for use in the playground, but we are absolutely clear that when it comes to lessons, noisy toys are not acceptable," he added.
Any parent who was unsure what the policy on electronic equipment was at their child's school should call and find out, he said.
"If in doubt, leave it at home altogether," Mr Brennan said.
Since April 2007, teachers have had the legal right to confiscate items from pupils.
Some schools have a "no gadget" policy where all non-educational equipment is banned or must be left out in lockers during lesson times.