The incident happened shortly after 11 p.m. on the corner of Saint Patrick and Stirling Streets.
Const. Yannick Ouimet said a dispute between three people started for reasons investigators believe are drug-related.
A 22-year-old man was stabbed several times in the upper body and was taken to hospital where he remains in stable condition.
Ouimet said officers do not have a description of the suspects who fled on foot.