Four fire engines and around 25 firefighters responded to a fire in a block of flats on Hanworth Road in Hounslow.
Part of a second floor flat, in a block of four floors, was damaged by fire. There are no reports of any injuries.
Control Officers took one call reporting the fire at 1452. Crews had the fire under control by 1535. Firefighters from Heston, Feltham and Twickenham fire stations responded to the fire.
Investigators believe the fire was started by a candle.