Seven catalytic convertors were taken from vehicles in the Acres area of Marlborough and George Lane on Thursday.
The thefts occurred between 11pm and 6.45am from vans and people carriers.
It will cost the owner of one of the targeted vehicles £1,000 to replace the stolen part.
Police believe they may have been taken for their scrap value, estimated to be between £100-£150.
Anyone with information should contact Marlborough police on 101.