Four fire engines and 21 firefighters and officers were called to a flat fire in Gifford Gardens, Hanwell.
Part of a three-roomed flat was damaged by fire. Crews rescued a woman from the ground floor. There were no reports of any injuries.
The Brigade was called at 0703 and the fire was under control by 0742. Fire engines from Ealing, Southall and Acton fire stations were at the scene.
The cause of the fire is under investigation.