Six fire engines rushed to the site and are being assisted by a helicopter. Firefighters battling the blaze are using jets and an ultra-high pressure hose. Crews from North West Ambulance service and Greater Manchester Police are also at the scene.
A witness said they heard an explosion coming from inside the building on Holland Street.
Neighbours took to social media to say thay had been told to evacuate as a precaution.
Greater Manchester Fire and Rescue Service said: “We are dealing with a significant incident in Holland Street, Denton.
“The fire involves a three storey warehouse building.
“If local, keep doors and windows closed and avoid the area.”
Several roads in the area have been closed while emergency services deal with the incident.
Highways England said the eastbound carriageway of the M67 was closed.
This is a breaking news story… More to follow