Five fire appliances and around 35 firefighters were called to a fire at a flat on Wandsworth Bridge Road in Fulham.
Half of a fifth floor flat was damaged by fire. One woman and two children left the property before the arrival of the Brigade. There were no reported injuries.
The Brigade was called at 9am on Wednesday and the fire was under control by 115am. Fire crews from Fulham, Wandsworth, Chelsea, Battersea, Tooting, Clapham, and Kensington fire stations attended the scene.
The cause of the fire is believed to be accidental.