Four fire engines and around 25 firefighters were called to a fire at a flat on Restons Crescent in Eltham.
Part of a four-roomed flat on the fourth floor of a five-storey block was damaged by the fire. Two adults and two children left the flat before the Brigade arrived. One woman was treated at the scene for smoke inhalation by London Ambulance Service crews. A further 20 people left neighbouring properties before the Brigade arrived.
The Brigade was called at 1306 and the fire was under control by 1513. Fire crews from Sidcup, Lee Green and Bexley fire stations were at the scene.
The cause of the fire is under investigation.