Thieves broke into a barn and made off with a quad bike.
On Friday night, between 7.30pm and 9.50pm the crooks used a van or trailer to steal the red and black Honda TRX500 quad bike from a barn in Boarstall.
Police are hoping to track down the bike, as it has distinctive grey tape on the seat.
PCSO Chris Kidd from Bicester police station said: “This is situated on the B4011 which leads from Thame into Bicester.
“Offenders would have to use a vehicle with a trailer or a large van type vehicle to put the stolen quad bike in.
“If anybody saw any vehicle in the area as described above, please contact me via the Thames Valley Police Enquiry Centre on 101.”
If you don’t want to speak directly to the police you can contact Crimestoppers anonymously on 0800 555 111.