Several fire engines attended the scene, together with ambulance response cars.
The incident happened on the A27 in Mill Road, Hove and emergency services were at the scene at around 5.30pm.
Emergency response teams were spotted with equipment in bushes on the embankment with the road.
The road was closed to traffic in both directions.
A Sussex Police spokesperson said: “Emergency services were called to a report of a vehicle which had left the road and gone down an embankment off Mill Road, Brighton, on Saturday (October 12) at about 4.30pm.
“One person in the car was taken to hospital to be checked over. The road was closed for over three hours for vehicle recovery.”
A spokesperson for East Sussex Fire and Rescue Service said: “We were called at 4.48pm on October 12 to a car that had come off the road at Mill Road, Brighton. Crews from Preston Circus assisted in the release of two casualties from the vehicle who were placed in the care of the ambulance service.”
A South East Coast Ambulance Service spokesperson said: “South East Coast Ambulance Service (SECAmb) were called to Mill Road, Brighton, at approximately 4.50pm on Saturday (October 12) following a report of a single vehicle collision.
“Crews attended and treated two patients at the scene before taking one to the Royal Sussex County Hospital in Brighton for further treatment.”