Police are appealing for witnesses following a collision between a motorcycle and a Ford Focus car at Wartling.
The two vehicles, which were travelling in opposite directions, collided in Wartling Road, near Lions Farm at about 12.25pm on October 20.
The motorcyclist was flown to the Royal Sussex County Hospital in Brighton where he remains in a serious condition. The couple in the car were unhurt.
A Sussex Police spokesman said; “Anyone who saw what happened, or who saw either of the vehicles involved just beforehand, is asked to contact us on 101 quoting Operation Pennock.”