Six fire engines and 35 firefighters and officers were called to a fire at a house in Mount Pleasant Road, Kensal Rise.
A detached house was gutted by the blaze.
There is not believed to have been anybody in the property at the time of the fire and there were no reports of any injuries.
The Brigade was called at 0451 and the fire was under control at 0648. Fire crews from Willesden, North Kensington, West Hampstead, Park Royal and Wembley fire stations attended the scene.
The cause of the fire is under investigation.