Six fire engines and around 40 firefighters were called to a fire at a flat on Boston Manor Road in Brentford.
Part of the roof of the building was damaged by the fire. Around 15 people left the building before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 2307 and the fire was under control by 0049. Fire crews from Ealing, Heston, Chiswick and surrounding fire stations attended the scene.
The cause of the fire is under investigation.