Witnesses said about a dozen Finks Outlaw Motorcycle Gang members leapt into a vicious melee at the vintage car festival on Saturday, throwing tables and chairs, while families dined on Marine Pde at Coolangatta.
A 61-year-old bystander was taken to The Tweed Hospital when a bikie punched him in the head for taking a photo of the fracas on his mobile phone.
The brawl outside Bellakai Restaurant, which took place on one of the busiest days of the festival, shocked community leaders and has prompted calls for action against bikies.
Festival organisers called the brawl "disappointing" and will meet police to discuss ways to keep thugs out of future events.
One witness, who did not want to be named fearing retribution, said he watched in horror while the fight broke out metres away from his daughter and two-year-old granddaughter.
He said a group of 12 Finks, wearing club colours and supporters gear, were walking down Marine Pde about 3.30pm when they set upon five men who stepped out of Bellakai Restaurant.
"They're absolute thugs," he said. "They picked up tables and chairs and were throwing them. You can't believe when you're family gets caught in it. I mean, she could have been hit with a table."
Bellakai Restaurant owner Kylie Hayden would not comment on the incident.
A police spokeswoman said the 61-year-old man took a photo when a classic car was damaged in the brawl.