Ten fire engines and around 70 firefighters are tackling a fire in a two storey warehouse on North Circular Road in Neasden.
Half of the first floor is alight.
The A406 is closed eastbound in Neasden and the Staples Corner flyover is also closed wetsbound.
The Brigade was called at 2.38am.
Fire crews from Willesden and surrounding fire stations are attending the scene. The cause of the fire is not known at this stage.