Twenty fire engines and around 125 firefighters have been tackling a fire at a hotel on Chiltern Street in Marylebone.
The Brigade's 999 Control officers were first called at 1452 and deployed fire crews from Euston, Soho, Paddington, West Hampstead, Kensington, Chelsea, and surrounding fire stations.
The incident was under control by 2007.
Crews worked hard over a number of hours in challenging circumstances in a complex historic building and successfully contained the fire to one property, preventing it from spreading to neighbouring properties.
Firefighters will remain on scene throughout the night damping down hotspots.
The fire started in ducting and spread from the ground floor to the roof of the four-storey hotel with a restaurant on the ground floor. The blaze spread to the second and third floors of the building.
Around one hundred people evacuated the building before the Brigade arrived, and no injuries have been reported.
The cause of the fire is under investigation.