The incident happened late on Saturday night in Kirkcaldy.
A 27-year old man was attacked on Charlotte Street shortly after 11pm.
The area was sealed off along with part of the adjacent Esplanade.
A Police Scotland spokesperson said: “Officers received a report of a 27-year-old man having been seriously assaulted on Charlotte Street in Kirkcaldy around 11.20pm on Saturday.
“The man was taken to the Royal Infirmary of Edinburgh, where he remains in stable condition.
“Officers are following a positive line of enquiry.”