Four fire engines and around 25 firefighters were called to a flat fire on Thurtle Road in Hackney.
Part of a four roomed flat on the first floor of a four floored block of flats was damaged by fire.
Around 20 people left the building before the Brigade arrived.
The Brigade was called 2311 and the incident was over by 0004. Fire crews from Shoreditch, Bethnal Green and Stoke Newington fire stations were at the scene.
Fire investigators believe the cause of the fire was due to the careless disposal of smoking materials.