Fifteen fire engines and around 100 firefighters were called to a fire at a warehouse on Minerva Road in Park Royal.
Half of a warehouse used as a bakery was damaged by fire. There were no reports of any injuries.
The Brigade's 999 Control Officers took 11 calls to the blaze.
Station Commander Mark Nunan, who was at the scene, said: "On arrival, crews were faced with heavy smoke coming out of the building but firefighters worked incredibly quickly to get the fire under control. Smoke has now subdued.
"One of the Brigade's 32-metre turntable ladders was used as an observational tower, providing an aerial view of the incident.
"Firefighters are expected to remain on scene throughout the night."
The Brigade was called at 1754 and the fire was under control by 1856. Fire crews from Park Royal, Acton, Willesden, Wembley and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.