Four fire engines and around 25 firefighters were called to a flat fire on Malvern Road in Maida Vale.
Part of a basement flat in a six-storey block was damaged by the fire. There were no reports of any injuries.
Station Officer Graham Danbury, who was at the scene, said: "The fire was in a bedroom in a basement flat, but the flat could only be accessed from the ground floor which proved difficult.
"However crews managed to quickly gain access and tackled the fire before it really took hold and the fire was contained to the bedroom, with smoke logging in the rest of the flat.
"There was no one inside the property at the time of the fire so fortunately no one was injured."
The Brigade was called at 0914 and the fire was under control by 0948. Fire crews from Paddington, North Kensington and West Hampstead fire stations were at the scene.
The cause of the fire is under investigation.