Four fire engines and around 25 firefighters were called to a fire at a disused building on Cranford Lane in Harlington.
An abandoned forklift in the building was completely destroyed by fire. There were no reports of any injuries.
The Brigade was called at 1512 and the fire was under control by 1703. Fire crews from Heathrow, Hillingdon, Southall and Hayes fire stations attended the incident.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police.