Eight fire engines and around 60 firefighters were called to a fire at a caravan and motor home storage site in Folkes Lane, Upminster.
A total of 17 motor homes, 10 caravans, two cars, three trailers and one boat were destroyed by fire. A further five caravans, two motor homes, four cars and a shipping container were also damaged by fire.
One person left the site before the arrival of the Brigade. There were no reports of any injuries.
The Brigade was called at 0516 and the fire was under control at 0746. Fire crews from Harold Hill, Hornchurch, Romford, Dagenham and Wennington fire stations, along with colleagues from Essex Fire and Rescue Service, attended the scene.
The cause of the fire is believed to be accidental.