Four fire engines and around 25 firefighters tackled a fire at a restaurant and commercial unit on Wandsworth Road in Perivale.
Half of the ducting and part of a flat roof were damaged by the fire. Three people left the building before the Brigade's arrival. One person was rescued from the flat roof by firefighters using a ladder. There were no reports of any injuries.
The Brigade was called at 0832 and the incident was over for firefighters at 1035. Firefighters from Wembley, Ealing and Northolt fire stations attended the scene.
The cause of the fire is under investigation.