David Green, 76, went missing from his home in Luton at about 5.30pm last night.
Bedfordshire Police has said he has links to the Edmonton area of London, and may also be in Portsmouth or St Albans.
In an appeal on Facebook the force said they were concerned for David’s welfare and asked anyone with information to get in touch.
If you can help call 101, asking for Bedfordshire Police, and quote reference 404 of August 25.