Police are investigating a fire at the former Moorcock Inn, Waddington, in the early hours of yesterday morning.
Two fire engines from Clitheroe were called to the building, which was closed down in 2010, at 5am and they used two hosereels to put the blaze out.
Crews wearing breathing apparatus also used a thermal imaging camera inside the derelict building.
No injuries were reported and police and fire chiefs are now looking into the cause of the fire.
Suspected arsonists struck at the former pub in Slaidburn Road in April last year.
Firefighters feared children were trapped inside the building at first and they discovered a blaze had been set in the former ballroom of the old pub.
The historic inn, which was once a top venue for weddings in Lancashire and was visited regularly by celebrities, has been the subject of much debate since it closed down.
Ribble Valley Borough Council has rejected plans to demolish the building and replace it with four houses.
Local residents have described the building, that has fallen into disrepair, as a "blot on the landscape."