The man had "severe injuries" and was found by passersby on St-Hubert Street near Jarry.
Const. Danny Richer said the man suffered injuries to his upper body, but the nature of those injuries was not disclosed.
The man was taken to hospital where he was pronounced dead.
"The investigators have to look [at if] it is a criminal incident. A car accident? All of these things are being looked at by investigators," Richer said.
Saint Hubert Street between Jarry and Mistral was closed off for the police investigation.