Emergency services responded to reports of a motorcycle and truck crash on the Princes Highway, Falls Creek in Friday afternoon.
NSW Ambulance paramedics treated the rider, a 63-year-old man for head injuries, before he was airlifted to St George Hospital in a serious but stable condition.
The driver of the truck was uninjured, returned a negative breath test at the scene and was taken to Shoalhaven Hospital for mandatory testing.
Officers from South Coast Police District have commenced an investigation into the circumstances surrounding the crash.
Anyone with information – or any available dashcam/phone footage – of the crash is urged to contact Nowra Police Station or Crime Stoppers on 1800 333 000.