Four fire engines and around 25 firefighters were called to a fire at a flat in Harlesden Road in Willesden.
Part of a flat on the 10th floor of a 12 storey block was damaged by fire. There were no reports of any injuries.
The Brigade was called at 2340 and the fire was under control at 0036. Fire crews from Willesden, Park Royal, North Kensington and West Hampstead fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police Service.