At just after 10pm last night (4/11), there was a collision between a blue Audi A3 and a pedestrian in Amersham Road, Hazlemere.
The pedestrian suffered serious injuries and has been taken to the John Radcliffe Hospital in Oxford, where he remains at this time.
The driver of the blue Audi was not injured in the collision.
No arrests have been made.
Investigating officer PC Matt Carson, of the Roads Policing Unit based at Amersham police station, said: “This collision has occurred just after 10pm on Friday and I am appealing to anybody who witnessed it to please get in touch with Thames Valley Police.
“I would be particularly keen to hear from anybody who may have dash-cam footage of the collision or the moments leading up to it to please check this and contact us.
“You can do so by making a report online or by calling 101, quoting reference number 43220498111.”