Four fire engines and around 25 firefighters tackled a fire on Green Lane in Chadwell Heath.
Half of the first floor of a two-storey mid-terraced house was damaged by fire. One man was taken to hospital by London Ambulance Service crews suffering from smoke inhalation. Another man was treated at the scene.
The Brigade was called at 0206 and the fire was extinguished by 0303. Crews from Dagenham, Ilford and Hornchurch fire stations attended the scene.
The cause of the fire is under investigation.