Five cars in Rothwell were damaged whilst parked on Saturday night.
The cars were parked unattended on a garage forecourt in Glendon Road sometime between 4pm on Saturday, March 21, and 10am on Sunday, March 22.
It is believed the offender/offenders walked over the roofs of the cars, causing dents to them all.
Police would like to speak to anyone who may have witnessed the cars being damaged or who may have any information regarding it.
Witnesses, or anyone who knows anything about this incident, can call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.