Four people, including a 15-year-old girl, have been charged with assault. The 46-year-old male victim received numerous cuts and abrasions to his body in the brawl on William Street around 10.20pm (WST) on Wednesday.
A 45-year-old man and a 15-year-old girl, both of Innaloo, have been charged with being armed in public, and assault.
A 40-year-old Innaloo woman and a 23-year-old Wanneroo woman have also been charged with assault.
Police are calling for witnesses, and have issued a description of a man they believe can assist them.
He is described as dark skinned, around 175cm tall with slim build and short dark hair.
He was wearing a white zipped-up jacket, with red around the upper chest and neck area and the numbers 05 on the back.
Witnesses are urged to call Crime Stoppers on 1800 333 000.