An investigation has been launched after a video of a brawl in a Balmoral Show bar tent emerged on social media on Friday night.
The Facebook footage shows around a dozen young men fighting while a crowd outside the tent looked on.
A number of security personnel moved in and were able to restore order.
Up to 100,000 people will have visited the annual event at the Maze showgrounds by the time the hundreds of exhibitors pack up later today.
A spokeswoman for show organisers, the Royal Ulster Agricultural Society (RUAS), said: “There was an altercation at the bar area, which was quickly brought under control by the event security personnel and we believe no one was seriously injured.
“It is sad that a few people resorted to this behaviour when tens of thousands of people enjoyed a fun family day out.”
The spokeswoman added: “The Society will be fully investigating this matter and appropriate action taken.”
Several punches and kicks were traded but there are no reports of anyone suffering serious injuries.
A number of punches were also aimed at some of the security staff who intervened.