A man has fallen to his death at a Sunshine Coast worksite on Thursday afternoon.

The 56-year-old man was working at a site on Duporth Avenue at Maroochydore when he fell from an unknown height.

He was believed to have been found unconscious at the bottom of a stairwell.

Critical-care paramedics were sent to the accident about 2:30pm and performed CPR on the man, but were unable to save him.

Workplace Health and Safety officers were investigating at the scene.