A young man was seriously assaulted in an attack which took place on the West Cliff on Monday night.
It is believed to have taken place around the beach, Pier Road or Khyber Pass area.
Police are appealing for anyone who heard or saw a disturbance in the area to contact them.
They say the 20 year-old man was attacked sometime between 9pm and 10pm.
Anyone who can help officers with enquiries is urged to contact North Yorkshire Police on 101, ask for Detective Constable Toby Forsdyke or Scarborough CID, email firstname.lastname@example.org or contact Crimestoppers on 0800 555 111.