Eight fire engines and around 60 firefighters responded to a fire on Christchurch Avenue, Kilburn.
The fire was located in a semi-detached property of two floors, converted into flats. Part of the first floor and the roof of the property were destroyed by fire. Five people left the property before the Brigade arrived, and all were removed to hospital by the London Ambulance Service.
One of the Brigade's 32m ladders was been deployed at the scene, and used to fight the fire from above.
The Brigade received the first of 18 calls reporting the fire at 0033, and Control Officers mobilised crews from West Hampstead, Willesden, North Kensington and surrounding fire stations to the scene. Firefighters had the incident under control by 0357.
The cause of the fire is under investigation by the Brigade.