Tricia Boisvert, 36, was last seen leaving her home in the South-West borough, most likely in her vehicle, on Friday night at about 7 p.m.
Const. Daniel Lacoursière said police have reason to fear for her safety.
"After examining the scene, the investigators think that maybe the victim ... could have been a victim of an abduction,"
The Montreal police major crimes division is now handling the investigation.
Police said it's possible Boisvert could be in the Ottawa or Gatineau region, where she's originally from.
Police are asking anyone who spots Boisvert or her car to phone 911 or Info-Crime Montreal at 514-393-1133.