Kenneth Walsh, who is also known as Kenny, went missing from the Burley area of Leeds on November 30.
The 71-year-old has not been seen since.
West Yorkshire Police is becoming increasingly concerned about his welfare, as the force is appealing to the public for help in tracking him down.
A statement from the force said: "Police need to confirm his welfare after concerns from another agency were raised."
Anyone who may have seen Kenneth is asked to contact West Yorkshire Police on 101, quoting log number 1821 of November 30.