Three fire engines and around fifteen firefighters attended a fire at a block of flats on Chatterton Road in Bromley.
Part of the ground floor flat was damaged by the fire.
Fire crews led one man to safety. He was suffering from smoke inhalation and was treated at the scene by London Ambulance Service crews.
Another man left the building before the Brigade arrived. He was then taken to hospital by ambulance.
The Brigade was called at 1705 and the fire was under control by 1812. Fire crews from Bromley and Orpington fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police.