Police are asking for the public's help to find 63-year-old Rosalind Forrester from St Leonards.
Rosalind, who has early onset dementia, has not been seen or heard from since leaving her care home in Upper Maze Hill on Sunday night.
Sergeant Paul Elrick said: "The last time Rosalind was seen was at her home at about 6pm.
"We have been looking for her but now that it has gone dark we are becoming increasingly concerned for her safety.
"Rosalind is white, 5' 6" and has thinning shortish dark grey hair.
"She is wearing a cream cardigan with blue piping and a white ad blue floral print skirt.
"More distinctively, she walks with her arms stretched out in front of her so anyone who she will stand out to anyone who sees her.
"Please contact us if you have any idea where Rosalind could be as we need to make sure she is safe."
If you see Rosalind or have any idea where she could be please call 999 immediately.