Two members of the New Boys street gang have gone on trial after a brawl outside an Adelaide tattoo parlour in April last year.

The men, Vincenzo Focarelli and Michael Syfris, were allegedly involved in a fight with members of rival group the Hells Angels outside a Hindley Street tattoo parlour.

The pair pleaded not guilty to the charge of affray.

The Adelaide Magistrates Court was shown security vision which allegedly shows the accused men outside the tattoo parlour before they were approached by members of the Hells Angels.

The prosecution alleges Focarelli swung a metal pole at the group and Syfris used a chair to hit a man.

Focarelli's lawyer, Sam Abbott, argued the men were acting in self-defence against what he described as a "full frontal all-out attack" on his client.