Robert Shaughnessy was last seen by friends walking in the 800 block of Coconut Circle West around 10 p.m.
Shaughnessy’s friends are concerned because he has health issues, deputies said.
Deputies said Shaughnessy is described as 6 feet 2 inches tall, 185 pounds with gray hair, blue eyes, and a full beard. He was wearing a white tee shirt and blue jean shorts.
Anyone with information on his whereabouts is asked to call the Collier County Sheriff’s Office at 239.252.9300.