Laptops, iPad minis and a Poppy Appeal charity box were all stolen by thieves targeting Twyn School, in Caerphilly town.
The break-in at the East View building happened during the early hours of Sunday, January 10.
PC Stuart Lewis, Caerphilly’s Crime and Disorder Reduction Officer, said: “This crime will certainly have an impact on the school pupils. Valuable teaching equipment has been stolen which will ultimately affect lessons.
“I’d like to encourage anyone who has any information on this burglary to report it to Gwent Police on 101, quoting log: 116 10/1/16 or anonymously via Crimestoppers on 0800 555 111.”