Six fire engines and around 40 firefighters tackled a fire on Walm Lane in Willesden Green.
The fire occurred at a three-storey building made up of a restaurant with flats above. Ducting running from the ground floor towards the top of the building was destroyed by fire. Most of a single-storey first-floor flat roof extension was damaged by fire. Part of a first-floor flat was also damaged.
Seven people left the restaurant and around ten people left the flats before firefighters arrived. There were no reports of any injuries.
There were a number of gas cylinders inside the building. They were cooled to an ambient temperature and removed as some cylinders can explode when exposed to heat.
The Brigade Control room received 18 calls about the fire.
The Brigade was called at 1200 and the fire was under control by 1241. Fire crews from West Hampstead, North Kensington, Hendon and surrounding fire stations attended the scene.
The cause of the fire has been recorded as undetermined.