Ten fire engines and around 70 firefighters tackled a fire on Netherwood Street in Kilburn.
The roof of a three-storey building, made up of a shop with flats above, was destroyed by fire. There were no reports of any injuries.
One of the Brigade's 32-metre turntable ladders was used to tackle the fire from above. The drone team also assisted by providing an aerial view of the fire.
People in the area were advised to keep their windows and doors shut due to smoke.
Station Commander Chris Swallow, who was at the scene, said: "Our crews worked hard to bring the fire under control and remained on scene throughout the night.
"Road closures were in place on Netherwood Street and on Kilburn High Road to allow us to work safely to extinguish the fire. Traffic was extremely busy in the area and we urged people to continue to avoid the area whilst we remained at the scene."
The Brigade's 999 Control Officers received seven calls about the fire.
The fire is believed to have been accidental and caused by a stray firework landing within the roof's gulley area.
A London Fire Brigade spokesperson said: “In the run up to Bonfire night, we encourage people to attend organised fireworks displays instead of using fireworks privately, but if you do choose to use fireworks, make sure you have enough space, buy them from a reputable, licensed seller and always look for a CE mark to make sure they’re safe. Never drink alcohol and set off fireworks and don’t throw fireworks or return to a firework once it has been lit.
“Remember that fireworks are explosives, and as such should be treated with respect and only used in accordance with the manufacturer’s instructions and the Firework Code.”
The Brigade was called at 2110 and the fire was brought under control by 2258. Crews from West Hampstead, Paddington, Willesden, Hendon, Kentish Town and surrounding fire stations attended the scene.