Bardsey Primary School will now have to foot the bill of clearing debris after it is thought someone took a chain saw to two trees, including the prized horse-chestnut.
Headteacher Sally Clark said that when the children came into school last Monday they said the conker tree had fallen down.
Teachers initially thought the youngsters were joking, but were shocked after going outside to find out.
Mrs Clark said: “My first thought was they must have blown down but on closer inspection it was obvious they had been cut with a chain saw.”
She thinks the person who has felled the trees put the saw through to the school’s side of the fence and cut them down.
“Naturally we are horrified as the children loved gathering the conkers at this time of year and relished in the beauty of their shininess.
“Nobody had approached us asking permission to do this and our site is in a conservation area so permission should have been sought from the council to remove any trees from our site.
“Both trees were left abandoned on our site so the school is now having to fund the removal of the tress, at a cost of approximately £500, money that would be far better spent on the education of our children.”
A Leeds City Council spokeswoman confirmed that one of its officers attended Bardsey Primary School after it was reported that two trees had been felled without permission in a conservation area.
She added: “Neither of the trees were deemed to be unhealthy or a risk to safety therefore the matter will be investigated by our planning enforcement team.”