He was winched to safety almost five hours later and treated for shoulder and chest injuries, paramedics said. The man remains in a stable condition.
New South Police Sergeant Peter McMaugh said it was remarkable the man was alive.
"Police and paramedics were able to abseil to the man and administer first aid," Sgt McMaugh told Sydney's Daily Telegraph.
"Firefighters have had to trek through bushland. The terrain is very rough, making it complicated for rescuers and difficult to traverse.
"The male is very lucky at this stage that his injuries are not life-threatening."
Police said the backyard of the Bonnet Bay property, in Sydney's south, backed on to the rock face.
