The Toronto area dragnet on Tuesday involving 260 officers was the culmination of a two-year investigation targeting "the highest levels" of the 'Ndrangheta, the Royal Canadian Mounted Police said.
Taking out key players in the group has put a significant dent in its global criminal operations, the RCMP special forces enforcement unit added.
The 'Ndrangheta mafia families based in southern Calabria, Italy spread to include several dozen members grouped in insular and secretive cells in the Toronto area, according to a statement.
Police allege they "combined their efforts regionally, nationally and internationally in order to elude enforcement, expand territorial influence and secure sources of income."
The Toronto "families" are specifically accused of drug importation and trafficking, firearms trafficking, extortion, possession of the proceeds of crime, and laundering the proceeds of crime.
The 19 arrested, aged 26 to 66, are charged with a variety of related crimes, including conspiracy and trafficking of marijuana and cocaine.
Police seized three firearms, approximately 8.5 kilograms of what is believed to be cocaine, seven kilograms of marijuana and cash, as well as five vehicles in the raids.