Around 20 firefighters tackled a blaze at an old jute mill in Blairgowrie.
Emergency crews were called to the 19th century building, off Balmoral Road, just after 9.30pm on Friday.
A Scottish Fire and Rescue Service spokeswoman said that four appliances, using five hose reel jets, lighting and two ground monitors, fought the inferno through the night.
Crews left the scene, but returned on Saturday morning to carry out a final inspection and check for hot pockets.
The fire was brought under control at 10.21am.
It is understood the derelict building was being renovated at the time of the fire.
