Anthony Gardenal was last seen at the facility, located in the 1500 block of Florida Street, at about 12:30 p.m. Saturday, police said. Police said he walks with a limp and would probably not be able to find his way home due to the dementia.
Gardenal is described as a Hispanic man who is 6 feet 2 inches tall and weighs 175 pounds. He has brown eyes, gray hair and a light complexion.
He was last seen wearing a blue jacket with white stripes on the sleeves, a black t-shirt, blue jeans and black shoes.
He is known to frequent the downtown area, police said.
Anyone with information about Gardenal is asked to call San Francisco police at (415) 553-1396.