Four fire engines and around 25 firefighters were called to a fire at a flat on Stanley Road in Hounslow.
Part of a four-roomed flat on the first floor of the building was damaged by fire. Firefighters wearing breathing apparatus led one woman to safety via an internal staircase. She was taken to hospital by London Ambulance Service crews after suffering from smoke inhalation.
The Brigade was called at 1627 and the fire was under control by 1734. Fire crews from Heston, Feltham and Twickenham fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.