Hartlepool Neighbourhood Police Team have issued the warning to motorbike and and moped owners and say the Owton Manor area of town has become a particular target.
The spate of thefts have also resulted in a rise in nuisance riding.
Officers have asked people to keep their bikes locked up by using a chain lock through the back wheel and covering the vehicle when leaving it.
Hartlepool Neighbourhood Police Team said: “We're warning motorbike and moped owners of a recent increase in thefts, particularly in the Manor area.
"Unfortunately this has also led to an increase in nuisance riding of the machines.
“We want to remind owners to keep bikes protected as best they can – by property marking the parts of the bike and by keeping them safely locked up whenever they’re not being used as it can take thieves just a matter of minutes to steal them (when at home, store bikes in a secure shed or garage wherever possible).”
Officers have have advised motorbike owners to use the steering lock and remove the ignition key when parking up, use a disc lock to secure the front brake disc, or secure the bike to an immovable object.
If you have information on motorbike/moped thefts or their illegal/antisocial use you can report to Cleveland Police on 101 or pass information anonymously to independent charity Crimestoppers online at www.crimestoppers-uk.org or by phoning them on 0800 555 111.