The lorry overturned early this afternoon on the Millhouse Roundabout, in Washington.
Police are at the scene, and say it could take them a number of hours to recover the vehicle.
A man was taken to hospital after the incident, according to police, but his injuries are believed to be non-life threatening.
Drivers have been advised to avoid the area, particularly around rush hour.
A tweet from Northumbria Police said: "We're currently dealing with an overturned lorry on the Millhouse Roundabout in Washington.
"Recovery may take a number of hours, which may cause some disruption around rush hour.
"Try to avoid the area if at all possible.
"Thanks for your patience."
A statement from the force later added: “At about 12.49pm today, police received a report of an overturned lorry at Millhouse Roundabout in Washington.
“Emergency services attended the scene and a man was taken to hospital.
"His injuries are believed to be non-life threatening.
“The lorry is blocking one lane and there is heavy traffic in the area.
“Recovery of the vehicle may take a number of hours.
“We would advise road users to avoid the area if possible.”