George Dodds, 72, was reported missing at about 6.50pm yesterday after leaving his home on Woodlands View in Cleadon at about 1pm.
Inquiries to trace him have been ongoing since he was reported missing but so far police have been unable to locate him.
The officer leading the search for George is urging the public to be on the lookout after receiving reported sightings of him.
Detective Superintendent Lyn Peart, said: “Inquiries to try and locate George are ongoing but police and his family are growing increasingly concerned for his welfare.
“There have been some reported sightings but we still need the public to be vigilant and help bring him home safely.
“George has problems with his memory and he may appear lost or confused.
"So it is really important that if anyone sees him or has information about where he may be, then please get in touch with officers.”
Officers have released a picture of George in the hope that someone may have seen him since his disappearance.
He is described as white, of thin build and with short white hair. He is believed to be wearing a dark puffer jacket, blue trousers, dark shoes and a black beanie hat.
Anyone who may be able to assist police in locating him is asked to call 101 quoting log 901 25/04/19.