Sussex Police is unable to confirm exact details currently but said the A280 Long Furlong was closed and officers were at the scene.
West Sussex Fire and Rescue Service said it was a collision involving two vehicles and they were called to the scene at 6.32pm.
The Herald understands one man was unconscious.
Steve Taylor, from the Sussex West Road Policing Unit, wrote on Twitter the road was likely to be closed for a ‘significant time’.
The accident is believed to have happened at the northern end of the road near Findon Cricket Club.
The A280 is one of the roads being used as a diversion for the A27 while it remains closed at Shoreham following Saturday’s plane crash.
Did you witness the collision? Email [email protected]
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