Officials say, 84-year-old Henry King suffers from dementia and had been staying with a niece in Boothwyn, Pennsylvania. He argued with his niece last night and left the house.
Police have various agencies and the fire department helping with the search.
They are focusing on a wooded area in the 3000 block of Valley Forge Drive at a condominium complex.
King is from North Jersey, and police believe he may be trying to get back there.
He is 5'7" tall and about 160 pounds, wearing brown jeans, brown shoes, and a white shirt.
King has salt and pepper hair and walks hunched over with a limp.
If anyone has information contact the Upper Chichester Police.