Five fire engines battled flames after 100 tonnes of scrap metal caught fire.
Residents near a recycling site in Gravesend were advised to keep their windows and doors closed as crews fought to contain the blaze.
Firefighters were called to the site in Crete Hall Road just after midnight.
It took almost four hours to get the flames under control.
In an update at 3.45am, the fire service confirmed the flames were out.
There were no reported injuries.
The cause is unknown.
