Four fire engines and around 25 firefighters were called to a fire at a flat on Fairfield Road in Bow.
Part of a split level flat on the ground floor was damaged by fire. Around 15 people left the building before the Brigade arrived. One man was treated on scene by London Ambulance Service crews after suffering from smoke inhalation.
The Brigade was called at 1137 and the fire was under control by 1243. Fire crews from Homerton, Bethnal Green, Stratford and Poplar fire stations attended the scene.
The cause of the fire is under investigation.