Two fire engines and around 10 firefighters were called to a fire at flat on Kent House Road, Bromley.
A first floor flat was damaged by fire. One man left the property before the arrival of the Brigade. The man was treated at the scene for smoke inhalation before being taken to hospital by London Ambulance Service crews.
The Brigade was called at 1421 and the fire was under control at 1547. Fire crews from Beckenham and Forest Hill fire stations attended the scene.
The cause of the fire is under investigation.