Binh Le left his home at 893 South Second St. around 9 a.m., police said.
Officials say he is known to frequent the downtown area, including Le Pharmacy at the corner of S. 10th Street and Santa Clara Street and Vietnamese businesses in search of newspapers.
He is described as an 87-year-old Vietnamese man with salt and pepper hair, 5 feet 4 inches tall and weighing around 105 to 110 pounds. He was last seen wearing a gray wool cap with ear covers, a beige jacket and gray slacks, and usually wears brown sandals.
Anyone with information about Le or his whereabouts is urged to call 911 or Missing Person's Unit at 408-277-4786 and reference San Jose police case #13-160-0427.
(ABC7 News contributed to this report)