Six fire engines and around 40 firefighters were called to a flat fire on Watts Street in Wapping.
Part of a four-roomed flat on the third floor of a residential building was damaged by fire. Firefighters wearing breathing apparatus rescued a man via an internal staircase who was taken to hospital after suffering from smoke inhalation.
The Brigade was called at 0232 and the fire was under control by 0305. Fire crews from Shadwell and Whitechapel fire stations attended the scene.
The cause of the fire is under investigation.