Five fire engines and around 35 firefighters were called to a fire at a block of flats on Parkham Street in Battersea.
Part of a four roomed flat on the second floor was destroyed in the blaze.
The Brigade was called at 1344 and the fire was under control by 1500. Fire crews from Battersea, Clapham, Wandsworth, Kensington and Lambeth fire stations are attending the incident.
The cause of the fire is under investigation.