There are welfare concerns for Thomas 'Eddie' Power, who was last seen at Fiona Stanley Hospital where he was receiving medical treatment.
The 65-year-old resides in North Lake but is known to frequent the Mandurah area.
He is described as 170cm tall with a slim build, green eyes, light brown hair and has several tattoos on both forearms.
Police believe he is travelling on foot and it is not known what clothing he was wearing when he disappeared November 5.
Anyone with information is urged to contact Police on 131 444 and reference IR 131120 1000 16896.
Secret Harbour Golf Links to host WA's most prestigious golf tournament
Upgrades begin on Kwinana Loop Trail
Shire of Harvey councillors vote in favour of city status
Erskine syndicate shares in division one Lotto win
Man accused of chasing down boy in Greenfields car park before assaulting him and stealing bicycle
New logo, website, ticketing system for Mandurah Performing Arts Centre
Perth, Mandurah households and businesses urged to turn off sprinklers now
Wannabe barbers caught on CCTV in bizarre Rockingham break-in
Mandurah residents encouraged to have their say on proposed 4.95% rate increase, Long Term Financial Plan