Four fire engines and around 25 firefighters were called to a fire at a block of flats on Water Lane in Stratford.
A small part of the first floor communal lobby of the 11-storey building was damaged by the fire. Eight people were treated for smoke inhalation at the scene by London Ambulance Service crews.
The Brigade’s fire investigators believe the blaze was accidental and caused by the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: "We'd rather you didn't smoke at all, but if you are a smoker it's absolutely vital you ensure your cigarette is completely out when you've finished smoking it.
"If you don't, you risk causing a fire which could not only destroy your home but also cost you your life."
The Brigade’s 999 Control Officers took 10 calls to the blaze.
The Brigade was called at 2048 and the fire was under control by 2138. Fire crews from Stratford, Leytonstone, Leyton and Poplar fire stations were at the scene.
Safety advice for smokers