The incident happened at a property on Hullen Edge Road sometime between Wednesday, February 27, and Saturday, March 1.
An antique engraved Omega watch with a brown leather strap belonging to the 98-year-old victim was stolen in the burglary.
Detective Constable Craig Pearson, of Calderdale CID, said: “We are interested in hearing from anyone who has been offered a watch of this description for sale or who has information about its theft.
“At this time, we still have a three day window of when this burglary may have happened and we are keen to hear from anyone in the area who has seen or heard anything suspicious during this time.”
Anyone with information is asked to call DC Pearson at Calderdale CID via 101, quoting crime reference 13190110614, or to give information via the Live Chat facility on the West Yorkshire Police website.