A Figtree man was airlifted to hospital in a serious condition on Sunday afternoon, after coming off his motorcycle on a blind corner of Mount Keira Road.
Paramedics were called to the incident about 11.45am, after another group of motorcyclists found the man – aged in his 20s – lying on the road.
Ambulance NSW Illawarra duty operations manager Inspector Norm Rees said it was believed the man had been a lone rider, who may have come across a tree that had fallen across the road.
"It appears that he came off his bike, travelled about 10 to 17 metres and landed heavily on his head," Inspector Rees said.
“The other motorcyclists, who were not travelling with him, also came across the tree and were able to stop, which is when they found him.”
The accident happened near the Harry Graham Drive turn off.
When paramedics arrived on scene the man was reported to be “unconscious and agitated”.
He was treated for head injuries, a fractured leg and shoulder and extensive bruising.
Inspector Rees said the rescue helicopter was called in when the man's condition "deteriorated".
He was intubated at the scene and stabilised - which took more than an hour – before being transferred to the chopper, which landed at the Mount Keira archery park.
He was taken to St George hospital in a critical condition.