Four fire engines and around 25 firefighters were called to a flat fire on Philip Street in Plaistow.
A three-roomed flat on the first floor of the building was destroyed by fire. There were no reports of any injuries.
The Brigade was called at 1658 and the fire was under control by 1750. Fire crews from Plaistow, Poplar, Stratford and Millwall fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.