Four men and four women, aged between 27 and 44, were also arrested on suspicion of affray following the incident in the early hours of Saturday.
Police said two suspected triad gangs of around a dozen people each clashed at the intersection of Hing Wah Street and Shun Ning Street, apparently over issues with loans.
Officers said some of them were armed with what appeared to be metal rods.
“After the two sides fought and one side chased after the other briefly, they all fled the scene,” said Chen Chi-cheong, an assistant district commander in Sham Shui Po.
“When police arrived, officers also received a report about a 68-year-old man who collapsed on Hing Wah Street nearby… The man was sent to hospital, and was certified dead shortly after 4am on Saturday morning.”
Police said the man who died was believed to have taken part in the violence.
They added that they made the arrests after scouring footage from surveillance cameras across the city.