Four fire engines and around 25 firefighters attended a fire at a block of flats on Shoot-Up Hill in Kilburn.
An area of exterior walkway on the fourth floor was damaged by fire along with a small part of a flat. There were no reports of any injuries.
The Brigade received the first of seven calls at 1856 and Control Officers mobilised crews from West Hampstead, Willesden and Paddington fire stations to the scene. The fire was extinguished by 2026.
The fire is believed to have been caused by the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: "If you smoke it is vitally important you stub it right out, preferably in an ashtray.
"Always ensure your cigarette is completely out when you’ve finished smoking it. If you don’t, you risk causing a fire.
"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.”
