A large warehouse fire erupted in south-west Sydney on Thursday night, with more than 50 firefighters called to battle the flames.

Fire and Rescue NSW Superintendent Adam Dewberry said the blaze was reported about 6pm and the site was "totally involved" in fire when trucks arrived.

He said the situation was escalated to "fifth alarm" status, with 20 trucks and more than 50 firefighters at the scene at Rickard Street.

No injuries have been reported.

It is understood property is a furniture warehouse.

Footage from the scene showed fire billowing from a collapsed roof and streaming out of windows.

Superintendent Dewberry said the furniture inside the warehouse provided a high fuel load for the fire.

"It is too early to know what caused the blaze, the main effort at the moment is to get the fire out," he said.

"We will run a fire duty during the night and then we will start to look at where this fire started and how."

"It is going to take a number of hours to get this fire out but the main thing is the surrounding premises have been evacuated those people are safe." 

He was thankful no people were reported to be inside, and firefighters were working to stop flames spreading to neighbouring properties.

"It was pretty intense ... we have our hazards materials experts here, they will be monitoring the smoke to make sure it is not an ongoing concern."

Vehicles parked next to the warehouse were being moved away from the burning building.