Five fire engines and around 30 firefighters attended a fire at a hotel on Old Marylebone Road in Marylebone.
The fire occurred in an extraction system in the ceiling on the ground floor. There were no reports of any injuries.
The Brigade was called at 1409 and Control Officers mobilised crews from Soho, North Kensington, Kensington and West Hampstead fire stations to the scene. The fire was extinguished by 1635.
The cause of the fire has been recorded as accidental.