Four fire engines and around 25 firefighters tackled a fire at a waste transfer site on Civic Way in Ruislip.
Around 500 tonnes of waste in a pit 30 metres below ground level was alight. Approximately 40 tonnes was removed. There were no reports of any injuries.
The Brigade was called at 1428 and the fire was under control by 1705. Fire crews from Hillingdon, Wembley, Willesden and Southall fire stations attended the scene.
The cause of the fire is under investigation.