Thomas Dottore, 80, was last seen at the care home where he lives in the 2000 block of Forest Avenue at about 11 a.m., police said.
He uses a wheelchair but can move around without it and the chair was left at the care facility. He suffers from dementia and diabetes.
Police searched the area around the home for Dottore, alerted local law enforcement and checked hospitals and transit agencies but have been unable to find him.
He is described as a white man, 5 feet 7 inches tall and weighs 147 pounds. He was last seen wearing a blue sweater and white shoes.
He wears glasses and a wristband with his name and other information on it, police said.
Anyone with information about Dottore has been asked to call 911.