Six fire engines and around 40 firefighters attended a fire at a residential block on Picton Street in Camberwell.
The fire damaged four split-level maisonettes. Around 20 people left the properties before firefighters arrived and there were no reports of any injuries.
The Brigade received the first of 24 calls at 1633 and Control Officers mobilised crews from Peckham, Brixton, Lambeth, Dockhead, Old Kent Road and Dowgate fire stations to the scene. A 32-metre turntable ladder from Old Kent Road Fire Station also attended and was deployed as a water tower to help extinguish the fire from above.
The fire was brought under control by 1746.
The cause of the fire is under investigation.