Police are appealing for public assistance to help locate missing man Maxwell Ostler.
The 90-year-old was last seen at a tram stop at the corner of Bourke and Spring Streets in the CBD about midday.
He was wearing a fawn checked green shirt, olive green pants and black shoes and is described as 177cm tall with grey hair, solid build and clean shaven.
Police and family have concerns for his welfare due to his age and medical conditions.
Maxwell is known to frequent the Fairfield area and uses public transport.
Police have released an image of Maxwell in the hope someone recognises him and can provide information on his current whereabouts.
Anyone with information about Maxwell is asked to contact the Transit Safety Division on 9247 3800.