A collection of 21 Storm watches worth more than £2,000 in total was stolen from a house in Horsham while the owner was away last month.
The home in Cootes Avenue was targeted between January 23 and January 30.
Detective constable Chris Merryfield-Day said: “The victim is very upset by the burglary, particularly because he had collected the watches over a number of years and they were of sentimental value.
“If you saw anyone acting suspiciously in or around Cootes Avenue in the last week of January please contact us.
“We would also like to speak to anyone who is offered the chance to buy any of the watches cheaply.”
Anyone with information should email firstname.lastname@example.org quoting serial 1738 of 30/1, call 101 or contact the independent charity Crimestoppers anonymously on 0800 555111.