A young man who fell 20m down a cliff was rescued in a delicate operation in the early hours of this morning.

The 25-year-old fell from a cliff near his Bonnet Bay backyard, in Sydney's south.

It took around 40 minutes for rescuers to get to the man, before he was winched to safety by an ambulance helicopter just before 4.30am.

He was taken to St George Hospital for treatment.

Source: 9NEWS