The incident happened around 10:45 p.m. Thursday at Restaurant Le Bordelais, at 1000 Gouin West.
Police said three men broke into the restaurant and beat the two workers, a 51-year-old man and a 63-year-old woman.
The man suffered a head injury and the woman's injuries appear to be minor.
Const. Jean-Pierre Brabant of Montreal police said investigators are working with the victims and surveillance footage collected from the restaurant to try to identify the assailants.