A safe containing £430 was stolen from Seaford Funeral Services between 6pm on Tuesday December 10 and 7.45am on Wednesday December 11.
A rear window was smashed at the business in Cradle Hill Road and a search carried out.
The metal wall safe which was taken was described as silver with a black front.
Anybody who saw anything suspicious in the area or who has information about the burglary should call Sussex Police on 101 or email:firstname.lastname@example.org.
Alternatively they can contact the independent charity Crimestoppers free and anonymously on 0800 55 111.