Four fire engines and 21 firefighters and officers were called to a fire at a block of flats in Innes Gardens, Putney.
Part of a flat on the second floor of the block was damaged by fire.
One woman and two children left the flat before the arrival of the Brigade and a disabled woman in a neighbouring flat was escorted to safety by two members of the public
Two men who also left the building before the Brigade arrived were treated for smoke inhalation by London Ambulance Service crews before being taken to hospital.
The Brigade was called at 2018 and the fire was under control at 2127. Fire crews from Wandsworth, Fulham, Battersea and Hammersmith fire stations attended the scene.
The fire is believed to have been caused by candles being used following a power cut.