Six wards were evacuated after a fire broke out in Aberdeen Royal Infirmary in the early hours of Saturday.
The fire started in ward 34 in the multiple-storey main building of the hospital around 2am. A total of nine appliances with pumps attended the blaze, and around 100 patients had to be moved to other parts of the hospital.
There were no reports of serious injuries, although two males were treated for smoke inhalation, Grampian fire and rescue service said.
The service is now working with the police to determine the cause.