Firefighters were called out on Sunday night to battle a blaze in a derelict building in the grounds of the old Stobhill Hospital.
Crews were alerted to the fire at Balornock Road around 6.20pm.
Nearby residents spotted a thick plume of black smoke billowing above the disused hospital’s clock tower.
It took four fire appliances several hours to bring the blaze under control.
On Monday morning, firefighters remained on the scene working to make sure the area was safe.
No one was thought to be in the building at the time and the fire service is unclear about how the blaze started.
A police spokesperson said: “Police were called at 6.19pm to assist the fire service.”
He added that the main roads had remained open during the incident.
A spokeswoman for NHS Greater Glasgow and Clyde said: “Scottish Fire and Rescue are dealing with a fire in a derelict building on the Stobhill site.
“No patients have been affected and the hospital continues to operate as normal.”
The entrance to Clever Clogs Nursery, which sits close to the old hospital site, was blocked as emergency services secured the surrounding area.
An acrid smell hung in the air over the new hospital and the adjacent Marie Curie Cancer Care centre as well as nearby homes.
In May 2016, firefighters were also called out to a large blaze which broke out at a derelict mortuary in a disused part of the hospital campus, which is separate to the new Stobhill Hospital building.