Four fire engines and around 25 firefighters attended a fire on Fullwell Avenue in Fairlop.
Part of a first-floor maisonette was damaged by fire. One woman was rescued from the property by breathing apparatus crews and treated by London Ambulance Service crews.
The Brigade was called at 1440 and Control Officers mobilised crews from Hainault, Ilford, Woodford and Leytonstone fire stations to the scene. The fire was extinguished by 1534.
The cause of the fire is under investigation by the Brigade and Metropolitan Police.