Four fire engines and 21 firefighters and officers were called to a fire at a block of flats in Queens Road West, Plaistow.
A small part of a flat on the 12th floor was damaged by fire. One woman was led to safety by firefighters wearing breathing apparatus and was treated at the scene by London Ambulance Service. A further 20 people left the building before the arrival of the Brigade.
The Brigade was called at 2321 and the fire was under control at 0026. Fire crews from Plaistow, Stratford, East Ham, and Leytonstone fire stations attended the scene.
The cause of the fire is under investigation.