A motorcyclist's had stones and a stick thrown at him as he drove down the A340 near Aldermaston.
Thames Valley Police say the 56 year old was attacked on the road on Sunday 27th May.
He wasn't injured but his motorbike did suffer damage.
Officers have released a picture of a man (right) they want to speak to in connection with the incident.
He was dressed in a grey t-shirt with a white logo and blue knee length shorts.
Investigating officer PCSO Sarah Preston, of Neighbourhood Policing based in Newbury station, said:
“This incident could have been extremely dangerous after stones and a stick were thrown at a motorcyclist travelling along a road at speed.
“We are appealing for the individual pictured to come forward, or if anyone recognises him to contact us.”
Anyone with information's asked to call 101, quoting reference '43180166001', or Crimestoppers anonymously.