Six fire engines and around 40 firefighters were called to a fire at a block of flats on Shacklewell Road in Hackney.
Half of a five roomed flat on the second floor was destroyed by fire.
Fire investigators believe the fire was caused by the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: “If you're 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.
“Firefighters recommend that you have a look at our online Home Fire Safety Checker to make sure there are no hidden hazards in your home.
“The online tool will ask you a series of questions that will help us work out the level of risk in your home, or the home of someone you care for. It only takes a few minutes to get tailored advice to keep yourself and loved ones safe from fire.”
Smoking safety top tips
The Brigade was called at 1938 and the incident was over by 2048. Fire crews from Stoke Newington, Homerton, Islington, Bethnal Green and Tottenham fire stations were in attendance.