A brawl broke out in a crowd of more than 200 people outside a nightclub in Carlton on Sunday morning, police say.

Police swarmed to Queensberry Street after the melee erupted outside the Illusion Bar and Nightclub about 5.30am.

One woman was treated for minor injuries, a Victoria Police spokeswoman said, and officers deployed capsicum spray to bring the crowd under control.

Police said between 200 to 250 people were involved in the disturbance and a smaller number was involved in the fighting.