Two men called at a flat in Rectory Gardens, Broadwater, claiming that they needed to check water pipes at the address at 11.30am on Thursday, September 21, police said.
When they left the 71-year old woman realised that they had stolen 19 pieces of jewellery, mostly rings, bracelets, necklaces and chains, a police spokesman said.
These included a gold ingot necklace showing a calendar view of the month of November with diamonds in the 17th and 19th, a 1911 gold sovereign pendant and a gold medal with ‘Crumlin Pits” engraved on it, according to the spokesman.
Police describe both suspects as being white and around 5ft 10ins.
One was of medium build with dark hair and the other was of medium to large build with ginger hair, the spokesman said.
Detective Constable Greg Brown said: “This was a targeted crime at the home of a vulnerable elderly lady who is understandably very distressed at losing a lot of items of both high monetary and sentimental value.
“Please get in touch if you are aware of any such jewellery being offered for sale anywhere locally, or if you have any information about the men who have been described.”
Any witness or anyone with information is asked to contact Sussex Police online or by calling call 101 quoting serial 453 of 21/09.
You can also contact the independent charity Crimestoppers anonymously on 0800 555 111 (www.crimestoppers-uk.org).