Police are urgently seeking information to help locate Gregory William McCullough.
The 54-year-old was last seen driving a red Mazda 3 hatch with the registration 1ESF 799 in the Fremantle area around 12pm yesterday.
He is described as 178cm tall, having a medium build with brown hair and green eyes.
Gregory was last seen wearing blue ripped jeans and a blue shirt.
It is understood he has left home with out his medication, prompting the urgent welfare concerns.
Anyone who sees Gregory or the red Madza 3 hatch is asked to contact police immediately on 131 444.