The Yorkshire Air Ambulance was called out to a school in Lupset following reports of a seriously-injured teenager.
A spokeswoman for the air ambulance said a young teenager had been left badly hurt following an incident at Waterton Junior and Infants School on Manor Haigh Road.
The school is no longer in use and the boy had fallen.
It happened around teatime last night, Thursday, August 24 and the helicopter landed on the school site.
The Yorkshire Air Ambulance was able to confirm that a patient had been taken to Leeds General Infirmary.