Four fire engines and around 25 firefighters were called to a fire at a house on Atherstone Mews in South Kensington.
Part of the ground floor of a two-storey house was damaged by fire.
Two men left the property before the Brigade arrived. They were both treated by London Ambulance Service crews at the scene for smoke inhalation.
The Brigade was called at 0331 and the fire was under control by 0417. Fire crews from Kensington, Chelsea, Fulham and Hammersmith fire stations attended the scene.
The cause of the fire is under investigation.