Van owners in Gomersal and Oakenshaw are being asked to keep their wits about them after a spate of thefts in the last two months.
Police said 40 thefts from vehicles had taken place in June and July in the two areas, mostly from vans parked-up overnight.
Kirklees crime prevention officer Libby Walker said the thieves had particularly targeted commerical vehicles with tools inside.
“We recommend removing all tools from your vehicle when parking it up overnight, or, if this is not feasible, making sure any tools or other items are firmly secured inside the van,” she said.
“Make sure tools are permanently marked as yours, this could prevent a thief taking them as it makes them more difficult to sell.
“This spate of thefts should also serve as a timely reminder for all vehicle owners to ensure they lock their vehicles whenever they are leaving them unattended and to make sure there is nothing left on display inside.
Owners were also asked to make sure they know how their van’s fob and alarm systems worked.
The Batley and Spen Neighbourhood Policing Team are to drop leaflets off around the communities to offer more advice about how to stay secure.
If you see anyone behaving suspiciously or have information, call the Batley and Spen NPT on 101.