Dot was stolen from a property on Chitty Road in Toodyay between April 20 and June 8.
The caravan was affectionately christened Dot and is sorely missed by her owners, who have launched an appeal for her return on social media.
Sgt Geoffrey Dickson, officer-in- charge of Toodyay police, said the theft was an unusual case.
‘In the three years I have been here, I cannot recall another case of someone stealing a caravan,’ Sgt Dickson said.
He said local police were working with other officers in the region in an attempt to locate the van.
Dot’s registration number is 1TET 092 and it has a faded yellow stripe around it.
Anyone with information can call crimestoppers on 1800 333 000 or Toodyay police on 9574 9555.