A 25-year-old man with a gunshot wound to the leg was dropped at Campbelltown Hospital last night.
The man presented to the hospital about 11.45pm and police were contacted soon after, however they were unable to speak to the man due to his medical state.
Officers set up a crime scene at a Campbelltown home and removed several items for forensic analysis.
An investigation into the shooting is underway.
The 25-year-old is in a serious but non-life-threatening condition.
Anyone with information or who may have witnessed the shooting is urged to contact Crime Stoppers on 1800 333 000.