Four fire engines and around 25 firefighters were called to a fire on Ealing Road in Wembley.
Firefighters tackled a fire at a two-storey block of flats, where a flat on the first floor was partly damaged by the fire. One person left the property before the Brigade arrived.
The Brigade's Control office received 11 calls about the fire.
The Brigade was called at 1302 and the fire was under control by 1351. Fire crews from Wembley, Park Royal and Acton fire stations attended the scene.
The cause of the fire will be investigated.