Four fire engines and around 25 firefighters were called to a flat fire on Blythe Road in Hammersmith.
Part of a flat on the fourth floor of a six-storey block was damaged by the fire.
Three people left the building before the arrival of the Brigade. There were no reports of any injuries.
The Brigade was called at 2216 and the fire was under control by 2249. Fire crews from Hammersmith, Chelsea, Kensington and Fulham fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.