Eight fire engines and around 60 firefighters were called to a fire on Dukes Road in Park Royal.
A one-storey commercial building, used for laundry services, has been alight. The fire is now under control but firefighters will remain on scene through the morning to fully extinguish the fire and dampen down.
There have been no reports of any injuries.
The fire was producing a significant amount of smoke and people in the local area were advised to keep their windows and doors closed.
The incident is situated close to the westbound carriageway of the A40 Western Avenue. This could result in some traffic disruption during the rush hour period. Dukes Road is also currently closed, impacting access to other businesses on the industrial estate.
The Brigade received the first of eight calls at 0316 and Control Officers mobilised crews from Acton, Park Royal, Ealing, Wembley, Willesden, Hammersmith and Chiswick fire stations to the scene. Firefighters implemented a water relay system as part of firefighting operations. The appliances were stationed between the incident site and the nearest water hydrant, and then connected together by hose. This allowed crews to pump a constant supply of water to the scene of the fire.
A 32-metre turntable ladder from Wembley Fire Station has also been in attendance and deployed as a water tower to help extinguish the fire from above.
The fire was brought under control by 0537.
The cause of the fire is under investigation.