Police have expanded their search for 65-year-old Ian Collett who left his Canning Vale home on Saturday.
Police are now focusing their search for Mr Collett along Albany Highway heading away from Armadale towards Bedfordale.
The grandfather left his home on Saturday when he went for a walk.
There have been several unconfirmed reports of Mr Collett being sighted at various points along Albany Highway.
The last confirmed sighting on the man was around 3.50pm on Saturday at a convenience store on Abernethy Road in Byford.
Police are currently conducting an aerial search along with ground search by mounted officers, 40 police personnel and 50 SES crew.
Anyone who sees Mr Collett is asked to contact Police on 131 444.