Police are especially concerned about Mayo Quinabato's safety, as he suffers from encephalopathy and diabetes.
Quinabato is described as Filipino, about five feet eight inches tall, and weighing 200 pounds.
He was last seen wearing a pale grey jacket, blue shirt, khaki pants and blue shoes. He was also seen carrying a light sling bag.
Police said Quinabato has gone missing before, but always returned to the hospital.
Anyone with tips about Quinabato's whereabouts is asked to contact police at 51 Division at 416-808-5100 or Crime Stoppers at 416-222-TIPS (8477).