Update 5 Dec, 9.15am: 75-year-old Peter Slater has been located.
Update 4 Dec, 12.15pm: A search is underway from a man in his 70s missing from Dublin.
75-year-old Peter Slater was last seen in Leopardstown yesterday.
Gardaí say they are very concerned for his welfare, and that he may present as confused when approached. He is suffering from dementia.
He is described as being five foot six inches tall, with grey hair and of medium build.
When last seen, Peter was wearing a grey hoodie with white stripes on the arms and black Adidas bottoms.