Officers are asking for help to trace 81-year-old David Reaney, who was last seen at home in Main Road, Eyam, at around 6pm on Thursday, May 5.
On Saturday, May 7, a family member spoke to him, and he mentioned going for a walk in the Grindleford area.
David has not been seen or heard from since.
A Derbyshire police spokesperson said: “He is described as white, 5ft 9ins tall and of slim build. He has brown eyes and grey hair and wears glasses.
“Anyone who has seen David, or has any information about his whereabouts should contact us quoting reference 873 of 9 May.”
Facebook – send a private message to the force Facebook page
Twitter – direct message @DerPolContact
Website – use the o nline contact form
Phone – call 101
You can also anonymously contact the independent charity Crimestoppers on 0800 555 111.