Four fire engines and around 25 firefighters were called to a fire at a flat above a shop on the High Street in Uxbridge.
A four-roomed flat on the second floor of the building was destroyed by fire. There were no reports of any injuries.
The Brigade was called at 1748 and the fire was under control by 1903. Fire crews from Hillingdon, Ruislip and Hayes fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.