Three fire engines and around 15 firefighters were called to a fire at a house on Broomwood Road in Clapham.
Part of the second floor of an end of terrace house was damaged by fire. Four adults and two children left the property before the Brigade arrived. One woman was treated on scene by London Ambulance Service crews.
The Brigade was called at 1414 and the fire was under control by 1502. Fire crews from Battersea, Tooting and Chelsea fire stations attended the scene.
The cause of the fire is under investigation.