Firefighters from Wokingham and Wokingham Road fire stations rushed to the hump back bridge in Barkham Road - just outside Wokingham - at 10.45pm yesterday, along with police and ambulance crews.
The fire crews used hydraulic equipment to cut the top off a Nissan Micra and used a back-board to rescue the man - who is believed to be in his 30s.
He was then taken to Royal Berkshire Hospital for further treatment.
The driver of the other car, a Vauxhall, was in his 30s and after being checked over by paramedics it is thought his injuries were minor.
Officers closed the road to traffic for nearly an hour.