David Tunnel, 68, was last seen in the Balmoral Road area of Gillingham at 10.21am on Tuesday 2 May 2023.
He is described as white, slim built with blue eyes.
Mr Tunnel is believed to be wearing a suit with a white shirt. He may wearing a trilby style hat and carrying a suitcase.
He is believed to be either be in Gillingham or may be in the north London area and he may be using public transport.
Anyone with information is asked to call Kent Police on 999 quoting reference 03-0408.