Two fire engines and 10 firefighters and officers were called to a fire at a block of flats in Homer Street, Marylebone.
Part of the basement flat of the building was damaged by fire.
One man was rescued by firefighters wearing breathing apparatus. He suffered smoke inhalation and was taken to hospital by London Ambulance Service crews.
The Brigade was called at 1024 and the fire was under control at 1111. Fire crews from Paddington fire station attended the scene.
The cause of the fire is believed to be accidental and due to a hob being left on and igniting items stored on top of it.