The incident between two-vehicles happened on the M25 anti-clockwise just before 3.55pm today (January 26).
Two ambulances, a critical care paramedic vehicle, and a response car from the Essex and Herts Air Ambulance attended the scene.
Both patients were transported by road to Basildon University Hospital for further assessment and treatment.
The crash, which involved two vehicles and resulted in one car overturning, occurred near junction 30 (A13, Thurrock, Lakeside, Tilbury).
Emergency services, including Essex Police and Essex County Fire and Rescue Service, are at the scene.
Two of the four lanes remain closed as a result of the incident, causing congestion back to junction 1b of the A282 and through the Dartford tunnels to junction 2 (A2 Darenth interchange).
A spokesperson for East of England Ambulance Service said: “We were called just before 3.55pm to a road traffic collision on the anticlockwise M25 near South Ockendon.
“We sent numerous resources including two ambulances, a critical care paramedic vehicle and a response car from the Essex and Herts Air Ambulance.
“Two patients were transported by road to Basildon University Hospital for further assessment and treatment.”
