Six fire engines and around 40 firefighters were called to a flat fire on British Grove in Chiswick.
Part of a four-roomed flat on the third floor of the building was damaged by fire. There were no reports of any injuries.
Sub Officer Daniel Scarlett, who was at the scene, said: “On arrival crews were faced with smoke coming out of the third-floor window and discovered a fire in the kitchen of the flat.
“The residents were out of the building before the Brigade arrived and crews worked quickly to stop the fire from spreading and causing further damage.”
The Brigade was called at 0137 and the fire was under control by 0233. Fire crews from Chiswick, Hammersmith, Acton, Fulham and Richmond fire stations attended the scene.
The cause of the fire is under investigation.