Eight fire engines and around 60 firefighters tackled a flat fire on Holland Road in Kensington.
A basement flat within a five-storey terraced building was partially damaged by fire. There were no reports of any injuries.
The Brigade was called at 1352 and the fire was under control by 1525. Crews from Hammersmith, Kensington, Chelsea and surrounding fire stations attended the scene.
The cause of the fire is believed to be accidental and is under investigation.