Tradesmen are being warned to lock their vehicles after a number of vans containing valuable tools were stolen.
A police spokesman said 13 vans had been taken in the Corsham, Box and Chippenham areas this year.
Officers believe the thefts were opportunistic, with the thieves noticing the vans were not secured.
The spokesman advised tradesmen to always lock their vans, not to leave valuables on display, and to remove tools at night.
Anyone with information is asked to call the force.