Four fire engines and around 25 firefighters were called to a fire at a terraced house converted into flats on Chesterton Road in Ladbroke Grove.
Half of the lower ground floor and part of the ground floor of the four-storey building were damaged by the fire. One man and one woman left the building before the Brigade arrived. They were both taken to hospital by London Ambulance Service crews.
Sub Officer Ian Griffiths, who was at the scene, said: "Crews were faced with an intense fire on arrival and worked hard to bring the blaze under control and stop it spreading throughout the building."
The Brigade's 999 Control Officers took eight calls to the blaze.
The Brigade was called at 2225 and the fire was under control by 2345. Fire crews from North Kensington, Kensington and Paddington fire stations were at the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.