Police are appealing for information after the assault in Maryhill.
The incident happened at around 9.15pm on Sunday, May 1, when two men and a woman were seriously injured when they were assaulted outside a restaurant on Maryhill Road, near the junction with Glencloy Street.
The trio were all taken to Glasgow Royal Infirmary for treatment - the men aged, 21 and 51, sustained serious head injuries, while the 52-year-old woman had a head injury.
Detective Constable Iain Cooper said: “Three people were seriously injured and we are keen to speak to anyone who may have seen what happened.
“The area would have been busy at the time with restaurants and takeaways open so I urge anyone with information that could assist with our investigation to come forward.
“If you can help please contact Police Scotland on 101, quoting incident number 3763 of Sunday, 1 May, or make a call anonymously to the charity Crimestoppers on 0800 555 111.”