A bronze bird bath worth £9,000 was stolen from the back garden of a home in Rotten Row in Lewes.
The sculpture called Noah’s Plate is 60 centimetres in diameter and has small animals and octopuses around the edge.
Sussex Police said the theft took place between mid February and the beginning of March.
The owner was away in February and believes it may have been stolen then.
Inspector Rob Lovell said: “This bronze sculpture is very distinct in style and of great sentimental value to the owner.
“We are really keen to trace the sculpture and return it to its rightful owner as soon as possible.
“I would encourage anyone who has information about its whereabouts or saw anything suspicious in the area at the time to get in contact with us.”
Any witnesses or anyone with information is asked to email email@example.com or call 101, quoting serial 0943 of 04/03. Alternatively, call the independent charity Crimestoppers anonymously on 0800 555 111.