Nelson firefighters were called out to a fire at a house in David Street, Barrowford, shortly after 8pm last night.
On arrival at the scene, two crews wearing breathing apparatus found that a chimney fire that had spread to wooden timbers around the chimney breast.
The crews extinguished the fire using hose reels and positive pressure ventilation.
There was a large degree of smoke damage to the attic and first floor of the property, and moderate damage to the ground floor.
No persons were injured in the incident.