A 26-year-old man attending a dance music festival in western Sydney fell unconscious and died on Saturday, two years after another death at the same event.

The man, from Albury, was among thousands of revellers at the Defqon.1 music festival at Sydney International Regatta Centre in Penrith.

The man's friends administered first aid until NSW Ambulance paramedics arrived and he was taken to Nepean Hospital, where he later died.