Cape Town - Wynberg Boys' High will be closed on Thursday and Friday after a fire broke out in the school's C-block.
The City of Cape Town's fire services brought the fire, that broke out at about 01:00 on Thursday, under control.
It is not known yet what caused it.
The school said on its web page that there were no injuries.
Due to structural damage and to ensure the safety of learners, parents were asked to keep their children home for the rest of the week.
The building will be inspected.