Five fire engines and around 35 firefighters tackled a fire at a block of flats on Cherry Orchard Road in Croydon.
Firefighters extinguished a small fire on a fourth floor balcony. There are no reports of any injuries.
The Brigade was called at 1843 and the incident was over for firefighters at 1930. Firefighters from Croydon, Woodside and Norbury fire stations attended the scene.
The cause of the fire is under investigation.