Statistics Canada figures show half of the families residing in the City of Montreal are couples while bigger families are moving to outside boroughs.
Real estate developers have been favouring one or two bedroom condominiums, often leaving some people wanting more affordable space for them and their children.
"Keeping families in Montreal will maintain the services that exist for families," said Martin Wexler, one of Montreal's housing administrators.
"If we don't have families, then schools will close, supermarkets and different services that target families which are dependent on services will not flourish --- so if you want to keep the infrastructure, and the social infrastructure of Montreal, we have to have families as an important part."
While the downtown region struggles to deal with the exodus, boroughs are dealing with the issue of meeting the demands for increased services.
Ville Saint-Laurent, for example, finds itself having to build a new library for its population, which now exceeds 90,000 people.
The current library was only meant to serve a third of that number.