Four fire engines and around 25 firefighters were called to a fire at a leisure centre on Philip Lane in Tottenham.
Part of a rear stairwell was damaged by the fire. Around 200 people left the building before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 1844 and the fire was under control by 1926. Fire crews from Tottenham, Stoke Newington and Walthamstow fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.