Firefighters rescued a woman from a fire at a house on Speranza Street in Plumstead.
A small part of the ground floor of a mid-terraced house was damaged by fire. Two men left the building before the Brigade arrived. A woman and two men were taken to hospital by London Ambulance Service crews.
Station Officer Mark Deane, who was at the scene, said: "Firefighters arrived to find a small fire in the kitchen of the house.
"Crews wearing breathing apparatus rescued one woman from the first floor of the building via an internal staircase.
"We would like to remind people to never try to tackle a fire yourself. Leave it to the professionals. As soon as you become aware of a fire in your property, get out, stay out, close the door behind you and call 999.
The Brigade was called at 0708 and the fire was under control by 0808. Four fire engines and around 25 firefighters from Plumstead, Erith and East Greenwich fire stations attended the scene.
The cause of the fire is under investigation.