At about 7.15pm, the drivers of a BMW and a taxi stopped in South Hill Road, where the driver of the BMW got out of his car, approach the taxi and kicked it.
When the taxi driver exited his car, the offender punched him in the face.
The offender is a white man in his late 20s, of slim build and about 6ft 1ins. He was wearing a dark coloured top and trousers, and driving a black two-door BMW, possibly with a 10 plate.
Investigating officer PC Craig Atkins, from Bracknell police station, said: “This stretch of road is quite busy with traffic and we are keen for any witnesses to come forward, especially if they can provide the registration number or part of it for the BMW.”
Anyone with information is asked to contact PC Atkins on 101.