Four fire engines and around 25 firefighters tackled a house fire on Riddons Road in Grove Park.
Most of the first floor and part of the loft space of an end-of-terrace house was damaged by fire. Three people left the building before the Brigade arrived. Five people were treated on scene by London Ambulance Service crews and three of them were taken to hospital.
The Brigade was called at 0750 and the fire was under control by 0928. Fire crews from Lewisham, Lee Green, Sidcup and Eltham fire stations attended the scene.
The cause of the fire is under investigation.