Four fire engines and around 25 firefighters were called to a fire at a shop with dwellings above on Roman Road in Bethnal Green.
Half of a bedsit on the second floor was damaged by the fire. Firefighters led one man to safety from the first floor via an internal staircase. He was taken to hospital by London Ambulance Service crews suffering smoke inhalation.
The Brigade was called at 1443 and the fire was under control by 1537. Fire crews from Bethnal Green, Shadwell, Whitechapel and Shoreditch fire stations were at the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.